If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you!


Introduction
There are two main things to consider when maintaining your hot tub water, Water Balance and Sanitation. There are a few different methods to sanitize your hot tub, Bromine and Chlorine being the most popular. However, I will only cover Chlorine, because that's what I know the best, thanks to Richard (Chem Geek). It is based on his famous Dichlor/Bleach method. If you're interested in Bromine, here https://www.troublefreepool.com/threads/how-do-i-use-bromine-in-my-spa-or-pool.84/ is an excellent writeup. However, Water Balance is related to all sanitation methods, so this could be helpful to anyone.

I will assume you have a fresh fill of water in your tub. If you don't and you're having problems, or it's close to the time to refill, you're better off just refilling your tub and starting over. Hot tub water should be changed every 3-5 months depending on usage. However, if your tub has serious problems, or you bought a used tub etc., you may want to decontaminate your tub using a product like Ahh-some.

In order to really maintain your water properly you need to test it. Test strips are ok for getting rough estimates, but IMO will make it more difficult to maintain your tub. It would be difficult for me to keep my tub as well tuned as it is by just using test strips. For a novice, I can see it being really difficult, especially if you have Well Water. Do yourself a favor and get a Drop Test kit such as the Taylor K-2006 or the TF-100.

One more note. Before I got my hot tub, I knew nothing about water chemistry. After I started studying hot tub water chemistry, I realized there was a lot more to keeping a hot tub water safe than I anticipated. However, after learning it, I realized it doesn't have to be difficult or time consuming. This may get a little technical, but once you learn it, you'll have no trouble keeping your water balanced and sanitized.

Water Balance
Water can be either Acidic, Balanced or Alkaline. If your water is not balanced, it could cause all kinds of problems. If it's too Acidic it could cause corrosion. If it's too Alkaline it could cause scaling. Both of which will reduce the effectiveness of your sanitizer. If your water is not balanced then your water is not safe for you, or your tub. So it's really critical to get this correct.

There are four main parameters to keeping your water balanced. Water Temperature, Calcium Hardness (CH), Total Alkalinity (TA) and Potens Hydrogen (pH). Assuming your water temp is around 100 degrees, we'll just focus on CH, TA and pH. The best way to test these is with a Drop Test kit, like the ones mentioned above. IMO Test Strips are just not accurate enough to test these, especially for a beginner.

Calcium Hardness: CH is basically the amount of Calcium in your water. The lower your CH, the higher your TA and pH need to be to have balanced water. The higher your CH, the lower your TA and pH need to be. The first thing you should do is test your CH in your tub. If you haven't filled your tub yet, test your tap water for CH using a drop test kit. If you have a water softener in your house, it will remove most of the Calcium from your water. That means you may get a different reading from your indoor sink then from the outdoor hose. Check both to make sure. If you have really bad well water i.e. lots of metals etc., you may want to fill your tub using the water softener water, then just add Calcium afterward. If your water is city treated water, you may be ok straight from the hose. Also, consider getting a pre-filter that attaches to your hose, and filters out some of the metals.

Here's my recommendation. If your CH is much below 100 ppm, you should add calcium to bring it up to 130-150 range. If your CH is over 100, you can leave it alone and just make a note of what it is. The CH level will be used to determine your TA/pH levels. To raise Calcium you add Calcium Chloride, aka Calcium Increaser. You can find it at most Pool/Spa supply stores. The good news is you only need to add Calcium once per water change, because it will stay relatively the same until your next water change.

Potens Hydrogen: pH is the measure of acidity in your water. It's on a scale of 0 to 14, 7 being neutral. The human eye has a pH of 7.5, so the ideal range in Pools/Spas is 7.4-7.6 with a min of 7.2 and max of 7.8. However, and this is important, just because you have a pH of 7.5, doesn't mean your water is balanced. If your TA and/or Ch is too high, you could be forming scale in your tub. So it is very important to have balanced water along with an ideal pH.

Total Alkalinity: Alkalinity is a pH Buffer. High levels of TA will not allow pH to change from additions of acid or base. However, a high TA requires a low pH to have balanced water. On the other hand, very low levels of TA will allow the pH to change with very little acid. A very low TA level could cause your pH to drop to low levels, very fast with little acid. Also, the lower your TA, the higher your pH needs to be to have balanced water. So, as you can see, a very low TA can become very unstable.

However, pH will have a tendency to rise with aeration (i.e. use of jets and air), more so if your TA is high. Although, as long as you're not adding Acid (or anything with a lower pH) to your tub, the pH will not usually drop. Therefore, in hot tubs the problem is normally pH rise (or Drift), because of all the aeration. So, the trick is to get the TA high enough to not create an unstable situation, and low enough to not allow pH to rise too much.

Let me repeat the last sentence, because it's the single most important thing to keeping your water balanced. The key to having balanced water, without pH drift, is having the correct TA level. If you find your pH rises too high (>8.0) after using your tub, your TA is too high, and needs to be lowered. If you find your pH is too low and/or your water is continually acidic, your TA is too low and needs to be raised. By fine tuning your TA, you can get your pH perfectly balanced, that rarely needs adjustment.

SO, what's a good TA then? Because spas tend to have a lot of aeration from jets and because the water is hot, it is best to keep the TA low at around 50 ppm.

OK, how do we adjust TA then? If TA is too low, you just add Baking Soda to raise it. However, if TA is high, it's little more involved. You'll need Acid (Dry or Muriatic). Depending on how high your TA is will depend on how long it will take you. Plan on it taking around an hour to decrease TA by 100 ppm. So if your TA is 300 ppm, plan it taking around 2-3 hours. First, uncover your tub and turn on all your jets, air, blowers, waterfalls etc. Test your pH. When it's greater than 7.8, add enough acid to bring it down to 7.0. Keep aerating until your pH is 7.8 again (about 30 min), then add more acid and repeat. Every time you add acid you're lowering your pH and TA. When you get your TA tuned perfectly, your pH will rise to a level (i.e. ~7.6) and stop, then you know you're at your ideal TA level. If your pH is rising too high (>8.0), bring your TA down a little more. If your pH doesn't rise enough from aeration (after an hour or more), you over shot it and need to add a little Baking Soda to raise your TA. After a few days/weeks of monitoring it, you'll get your TA tuned perfectly. You may need to add a little Dry Acid once a week or two, but your water should be well balanced at that point.

I wouldn't go much below 50 ppm TA, because that could become unstable if you add any kind of acid. Also, if you have a high TA, above 100, you may need to add more acid in the beginning to get your pH down. Remember, TA is a pH buffer, so the higher the TA, the more acid you need to bring the pH down. It takes approximately 8 oz total of Dry Acid to bring TA down 100 ppm in a 350 Gal tub. However, the key is not to add too much acid all at once to bring your pH down under 7.0. That's why you should aerate in between adding acid.

Lastly, there is one more thing I haven't mentioned that you can add to your tub that will help buffer your pH, Borates. The easiest way to add Borates to your tub is to get a product called Gentle Spa. It is pH balanced, so there is no need to add acid to counter balance it. The ideal amount is ~50 ppm, and only needs to be added once per water change. That will help keep your pH from drifting from aeration. Not to mention, actually make your water feel silkier. I highly recommend it.

BTW, I'm purposely not giving the exact amounts of Calcium, Baking Soda or Acid to use, because PoolMath will calculate that all for you. Just enter your tub size at the top, enter the current level in the left column, then enter your goal amount in the right. It will tell you the amount and what you need to add. For instance, if you enter tub size of 320 gal, a pH of 7.8 in the left column and 7.0 in the right, it calculates .4 oz or 2 tbs of Dry Acid. All you need to balance your water perfectly is Calcium Chloride, Baking Soda, Dry Acid and The Pool Calculator.

Sanitation
I'm only going to discuss Chlorine here, because I don't know enough about Bromine to comment on it. This is based on Chem Geek's Dichlor/Bleach method. I have found this method to be very easy and safe to use. I have yet to have a problem. I don't want to get into pros and cons, because that's better suited for it's own thread. If you don't know his method, this should explain it to you. If you do know it, maybe this will help you execute it better. I'm not going to get too technical. I'm just going to discuss everything that's important to keep your tub sanitized easily. If you want more details, search through Chem Geek's posts. You'll have plenty to read. Disclaimer: I'm not trying to convince you to use this method. I'm just explaining it. Please weigh all options before making a decision.

There are really two main things happening when your pool/tub is being sanitized. Organic waste is being oxidized, and bacteria/viruses are being killed. Chlorine does both, very well. That's why it's the most popular sanitizer in pools and spas. However, in order for chlorine to be effective there needs to be a Free Chlorine (FC) level in your tub at all times. If it drops to zero, bacteria will multiply within hours. So the number one rule with using chlorine as a sanitizer is, never let it drop to Zero for any length of time. Now lets get started on the procedure.

The first thing we are going to use to sanitize our tub is Dichlor. Dichlor is actually two things, Chlorine and Cyanuric Acid (CYA). CYA is a chlorine stabilizer, which slows down dissipation from UV rays (sunlight). It also acts as a buffer to hold chlorine in reserve. Having CYA in your tub will stop the chlorine from dissipating as fast while waiting for something to do and buffers the harshness associated with chlorine. However, CYA also cuts down on the ability for the chlorine to sanitize. So in other words, the higher the CYA level, the longer the FC will wait in the tub, but the less effective the FC is. With no CYA in the tub, using bleach would be too strong and not practical to use. So, there needs to be a happy medium. Luckily, Chem Geek has come up with one for us. He suggests a CYA of ~20 ppm. Personally I use a CYA of 30 ppm for reasons I won't get into here. But I think Chem Geek would agree anywhere between 20-50 is fine. Where the problem comes in is when CYA gets too high (above 100) after weeks of using Dichlor. Then your FC needs to be really high to get the same sanitation effectiveness. That's why we switch to bleach after we get our CYA to 20-30. Bleach doesn't add anymore CYA.

So, I'm going to assume our target CYA is 30, but feel free to use 20 and adjust as necessary. I find that it's easier to keep track of how much Dichlor you're adding to the tub and calculate the CYA, rather than testing CYA with the drop test kit until you get a 30 ppm reading. For every 10 ppm of Dichlor you add to your tub, you add 9 ppm CYA. So roughly 34 ppm Dichlor will give you 30 CYA. On a fresh fill, and after your water is balanced by the above method, shock your tub with Dichlor to 10 ppm FC. Then over the course of the next several days, depending on bather load, add 24 ppm more FC using Dichlor. You want to keep your FC normally between 3-6 ppm every day. This means you will be testing your FC EVERY DAY.

For example: On one day you test your FC and it's 1 ppm. You'll then add 5 ppm FC to bring it to 6. The next day you test FC and it's 3. You then add 3 ppm FC. You will do this until you add a total of 34 ppm FC to your tub using Dichlor. After that, you then switch to using bleach (plain, no scent, not splashless, no Cloromax). Important: if you're not willing to test your tub everyday, at least for the first month or two, this method is not for you. I'd recommend another sanitation method

When you use your tub (this applies to when you are still using Dichlor or after you switch to bleach), the rule of thumb is, you'll use approximately 7 ppm FC per person per hour in a 350 gal tub. Now this will depend on a lot of things, water temp, cleanliness of the users etc. If it's just two people, after taking showers, using no swimsuits, with the temp at 98 you may only need 2 ppm FC/person/hour. However, if you have 6 people in their clothes, drinking (spilling) beer, with a temp at 102 causing everyone to sweat, you may need 20 ppm FC/person/hour. So this is where you may need to make a judgment call and/or experiment. Remember, the Chlorine has to do two things, Oxidize Waste, and Kill Bacteria. If your tub is being subjected to a lot of waste (sweat, beer etc), your FC will be used up and not be able to kill bacteria. Not good! So I'll give you two scenarios and how you might go about running an experiment. Remember, all this up front work is only necessary in the beginning, until you learn how much FC is being used in your tub. Once you know, it becomes easy to maintain. The rule of thumb is, assuming CYA is 20-30 ppm, FC should normally be between 3-6, with a min of 1 and shock to 12 once a week.

We'll go with the easy one first, two people, showered, no suits etc. (Note: Some people prefer to use the tub with very little FC. That's your choice. I'm just telling you how to determine how much FC you're using in a safe manner). Test your FC and add Chlorine to get to 5 ppm FC. After one hour of soaking test FC again. If you find you have no FC after an hour, next time start with 6 or 7. If you find you still have 3 ppm FC, next time it's safe to start with 3-4 ppm FC. Get it? The trick is to have the lowest amount of FC without ever dropping to zero. If you plan on staying in the tub longer than an hour, either start out with more FC, or add some during the soak. However, you don't want to get into the tub with the FC much above 8, unless of course you like a strong smell of chlorine. I got in once with FC at 10, and it was a little too much for me, and I like the smell of Chlorine.

On the other extreme. Full tub of people drinking, sweating etc. Do the same as above, but start out with more FC, maybe 6-8 ppm. Check the FC in an hour (or even a half hour). If you have no FC, you need to add some and check more often. If you still have FC, add some, and check again in the same time frame. It's the same as above, but you're just using more FC, more often. However, having the FC drop to zero for a short time with your lover, is not the same as with 4-5 other people, if you get my drift. So it's much more important to keep FC above zero at ALL times during a Hot Tub Party.

If you find you're having trouble keeping FC in your tub during parties, and/or you smell a foul odor during your soaks, you can add Potassium Monopersulfate (MPS or Non-Chlorine Shock) before (and/or during) your soak to help the Chlorine Oxidize waste. The only thing I would say is, go easy with MPS. Use only the amount needed and not much more. It is acidic and will lower your TA/pH if you use a lot. Start out with 1-2 tbs in addition to your normal FC, and see if that cuts down on the FC usage. Up it to 3-4 tbs, or add another 1-2 tbs during the soak if needed. MPS will help oxidize waste. However, it will not kill bacteria, so you still need FC. Also, you can use MPS as a shock once a week to help oxidize leftover waste, and reduce Combined Chlorine (spent FC).

Wow if you made it this far, you did pretty well. It seems like a lot to learn, but it's really not. I'll summarize it here.

Summary

Water Balance
If your CH is much below 100 ppm, raise it to ~150 ppm. Otherwise, make a note of it.
Adjust your TA to ~50 ppm. Use Baking Soda to raise it (unlikely to be needed), or Acid/Aeration method to lower it. It takes ~8 oz Dry Acid to lower TA by 100 ppm in a 350 Gal Tub. Don't add it all at once!
pH should be between 7.2-7.8. Aerate to Raise pH. Acid to lower it.
If pH creeps up too much (>8.0), lower TA. If pH is too low, and doesn't raise enough by aeration, raise TA.
Add ~50 ppm Borate. (Borox/Acid or Gentle Spa)
Calcium, Baking Soda, Dry Acid and Borates is all you need to balance your water.
Use PoolMath to calculate exact amounts to add.

Sanitation
On a fresh fill use Dichlor until you get to 20-30 ppm CYA. (10 ppm FC = 9 ppm CYA)
Then switch to plain bleach or liquid chlorine.
Never let FC drop to Zero for any length of time. Keep it between 3-6 ppm normally, min of 1 ppm, and shock to 12 ppm once a week.
Use MPS if needed before hot tub party's and/or once a week to help oxidation. Don't use more than needed, because it's acidic and may lower your TA/pH.
Dichlor, Bleach and MPS is all you need to keep your tub sanitized.
Use PoolMath to calculate exact amounts to add.

Lastly, get a drop test kit such as the Taylor K-2006 or a TF-100. Also get FC test strips. They come in handy for a quick FC estimate, during party's etc. The only two things you need to check regularly are FC and pH. Check them every day and after soaks. Adjust TA as needed. If you have your water well balanced, you'll rarely need to adjust your TA. You'll just be adding chlorine every day, and after soaks. Shock once a week, and/or after high bather loads. Use MPS if you have party's, and/or don't want to use as much chlorine. Easy as can be, and your tub is always ready.

I hope that helps you to understand Water Maintenance a little better. It helped me just to write. If I missed anything important please let me know, I'll be happy to add it.

Happy tubbing!

Hi All,

Recently I have been doing a lot of playing around with Grafana and InfluxDB v1.8.3. Mostly, in order to better manage and access my swimming pool automation, sensor and chemical control historical data.

Grafana makes it great to do so, since I can view the historical and current data in ANY context or time period that I wish. It appears that Grafana makes the management of pool automation data much better than anything that can be found bundled with the big 3 pool automation platforms.

But I also know that my current Grafana dashboard can be improved even more.

So, I am looking for other experienced Grafana/InfluxDB users out there that may wish to share their ideas and the fruits of their labor, etc.

Things like the following:

• Dashboard templates
• Panels
• Plug-ins

In other words, I wanted to start a collaboration thread of sorts here for the sharing of pool automation related Grafana ideas etc.
I’ll go ahead and post what I currently have and would hope that there might be a few other pool automation DIYers out there that happen on to this thread who may wish to do the same.

In full disclosure, I did not develop the dashboard that I am currently using from scratch.
I had started with my own dashboard originally, then I lost all of my work on “Docker” (which I had no concept of.) I then decided to download Grafana directly to my Mac and started over.

Initially, @tagyoureit had assisted me with the setup of InfluxDB and Grafana. When I informed him on what had happened, he was kind enough to share the dashboard that he was working on and I imported his dashboard template into my own. I can't thank him enough for all of his assistance in the course of this project!

I used much of his base work and set out to modify it to my own preferences, setup etc. Modifying some panels and using his templates to create some of my own panels. I even found a cool new Grafana “dial” plugin in which to incorporate.

Although my Grafana log files etc., reside on my Mac. InfluxDB resides on a Raspberry Pi solely dedicated for that task and pulls its data from the nodejs-poolController that resides on a different RPi.

Note 1: I should really note here that there is a companion piece of software that is in final stages of development/beta testing that really goes hand-in-hand with the Grafana output but I’ll share more on that later.
Note 2: The bindings directions for integrating InfluxDB with the nodejs-poolController can be found in the following link.

I did find three other threads and/or posts here on TFP that do mention the use of Grafana. I'll go ahead and include the links to them below.

Anyway, I have included below a screen capture of where I’m at presently. If anyone has any ideas on how my Grafana output can be improved/modified, or you wish to share your own InfluxDB/Grafana work, your input and contributions are certainly welcome.

Thanks in advance…
r..

I am replumbing my equipment pad. I would like to be able to isolate the heather and SWG. What is better, 3way valves or tees with a ball valve on each side.

Liner was leaking and had seen better days. I looked for the leak and could not find it and it was leaking at a decent enough rate that I would need to add water every few days. As it was I filled it back up 3 or 4 times over the past winter.

Not sure how old the liner was, it pretty much looked like this when I bought the house in 2013. They said it was only 3 - 4 years old but I doubt it, since it was pretty faded then. I think the pool was still closed when I made my offer on the house and closed at the end of July 2013

In the first year or two I found out the the conduit to the light niche was leaking. First fix with epoxy putty lasted a year or two. After that I dug and fixed it by replacing some of the conduit and making a better connection to the niche. Settling of the soil looks to be what caused it to originally fail.

Some before photos:

We live in central florida and are planning to do our own DIY pool by hiring a pool consultant who can help us with the design, securing the permit and suggest sub-contractors. Can anyone suggest a good consultant in Florida? TIA

New pool owner and we are wanting to warm up the pool for some thanksgiving swimming (hosting a bunch of family and thought that might be fun). Any idea how long it will take to heat up (will it even get up to temp when the nights are dipping down to freezing?)

(Edit to add: The pool is pretty large - 20x40 with a deep end + integrated spa and two tanning shelves. We have a gas heater 399K BTU. Water temp is 53 and we’d prob want to raise it 30 degrees.)

I am a 74 year old retiree. I recently purchased a house with a 11 year old pool (~23,000 gallons). I have completely replaced ALL the equipment, pumps (5), filters (2), heaters (2). and Chlorine generator. All are Pentair.
I was getting mixed results getting pool water tested by one Pinch-a-Penny, so I went to another one. Same inconsistent results.
I purchased a German photometric pool water tester (PoolLab 1.0) and started getting consistent results.
My big issue is with achieving a balance of pH & Alkalinity. I understand it is a typical problem. I have been alternately adding Muriatic acid and Sodium Bicarb (Arm & Hammer). I am very close. Current pH: 7.7, Alkalinity:90. I have read Robert Lowry's booklet on pool chemistry. This led to the discovery of adding Boric acid to stabilize pH. However, I understand the EU is dead set against this chemical and the local pool supply stores don't even test for it. I purchased a 55# bucket of Boric acid granules and added about half yesterday. Borate level today is between 20-30 ppm (test strip). According to Lowry's booklet the target borate level should be 50 and not exceeded. I added about another 10# today. I'll test tomorrow.
Looking for experience.

Hi All

My kids do swim team at a public indoor pool. Been hearing horror stories of kids picking up chlorine pucks, cloudy water, bandaids, etc. Decided to test the water with the TF-100 kit:

FC 3 ppm
CC 1.5 ppm
CYA 100
CH 725
TA 90

What is the collective wisdom? Safe to swim?

My understanding of the TFP philosophy applied here:
1. Shut the pool down.
2. Drain the pool. At least 75% water should be replaced. Get CYA to 25.
3. Stop using pucks and powder shock. They are likely causing stratospheric CH and CYA levels
4. Liquid chlorine, SLAM the pool. Don't re-open until SLAM is complete.

Recently, there have been a lot of questions from those living in moderate climates about using automatic freeze protection or running pumps to prevent freezing and what a pool owner should do when temperatures drop so I thought it might be useful to have a thread which dealt with the issue from both a practical and theoretical point of view.

But first a few thoughts about using pumps to prevent freezing. Running the pumps is not fool proof and power outages can obviously be a problem. Also, some pools have a lot of features and some are manually controlled so automatic freeze protection may not always be a viable solution. Plus electricity is expensive in many areas so having the pumps run all night is not always an attractive option. Given all these factors, I am not a big fan of using the pumps to prevent freezing, but there are alternatives for those that are interested.

Also, I wondered how long it would actually take for a pipe to freeze so I did some research into the physics of freezing pipes. Over the years, there have been several empirical university studies and the consensus is that for home plumbing in un-insulated spaces (e.g. attics), the "alert" temperature where pipe freezing and bursting can become a problem is below 20F. Above that temperature, freezing rarely occurs and bursting of the pipe is even rarer. But this is for small copper pipe in attics, not pool equipment so I had to look deeper.

The time it takes a pipe to freeze is dependent on several factors:

Size and dimensions of the pipe: More water in the pipe takes longer to freeze.
Pipe thermal conductivity: Copper is about 2000x more thermally conductive than is PVC.

But then there are also environmental conditions:

Air Temperature: The lower the air temperature is below freezing the faster freezing will occur.
Night Sky Exposure: Radiation losses can have a large impact on the heat loss.
Wind Speed: Wind blowing over the pipe greatly increases the heat loss of the pipe.
Location: Proximity to heat sources (e.g. side of house).

But a freezing pipe does not always result a bursting pipe. In fact, it rarely does. When a pipe freezes it freezes from the outside inwards and as the ice expands, the excess pressure is relieved through the center of the pipe until the pipe freezes solid. This alone will not burst the pipe. However, once the pipe is fully frozen and blocks the relief of pressure, the freezing ice up stream of that section of pipe may not have a path to relieve the pressure and only then does the pipe burst. This process is fairly well described in the following sources:

http://www.spokanecounty.org/data/buildingandplanning/disaster/DIS-FreezeBurstPipe.pdf
http://www.iccsafe.org/cs/PMG/Documents/DIS-FreezeBurstPipe.pdf
http://scifun.chem.wisc.edu/radio/pipefrez.html

So in order to take all these factors into account, I used standard thermal transfer equations to estimate the heat loss of a pipe when exposed to all these environmental conditions. I then ran a few experiments in my freezer to make sure the model was giving fairly accurate results, which it did.

So here are a few examples:



These results assume a minimum night time temperature of 20F, starting at 32F and the time to freeze only includes the time below 32F. So the average temperature is 26F over that time frame. There is some inherent margin included in these numbers because I assumed the water temperature started out at 32F which in most cases it is higher and it ignores the latent heat within the filter water which can act like a heat source for the rest of the plumbing.

Wind has a fairly large affect but visibility to the night sky has an even larger effect. Covering the exposed equipment can reduce the heat loss considerably from both of these factors and freeze times are much much longer. So the easiest thing a pool owner can do is cover the pad equipment and plumbing with a tarp. Adding a heat source underneath the tarp or cover would add enough margin to eliminate the need for running the pump or at least provide enough backup should the automated freeze protection fail.


The heat transfer model is available here for those who are adventurous:

Hydraulics 101 - Have you lost your head?


So if you would like to be able to go without automated freeze protection OR you would just like to have an extra layer of protection, then you can follow some of the suggestions listed below. The temperature ranges and time are using the thermal loss spreadsheet above which are fairly conservative freeze estimates (i.e. assumes 15 mph winds, full sky exposure with maximum radiation losses and ignores latent heat in filters and surrounding structures).

1. Air Temp 32F->25F->32F for <10 hours. Plumbing 1" and above is safe. Tarp or drain for smaller pipes.

2. Air Temp 32F->20F->32F for <10 hours. Plumbing 1.5" and above is safe. Tarp or drain for smaller pipes.

3. Air Temp 32F->15F->32F for <10 hours. Plumbing 2" and above is safe. Tarp or drain for smaller pipes.

4. Air Temp 32F->10F->32F for <10 hours. Plumbing 2.5" and above is safe. Tarp or drain for smaller pipes.

5. Air Temp 32F->0F->32F for <10 hours. Tarp equipment and use an incandescent light bulb underneath OR use heat tape available at your local hardware store.

6. Air Temp <0F. Drain all equipment and plumbing.

Note that when air temps get close to 0F, water temps are likely to be below 40F so there is no harm in draining the equipment and letting the pool go idle since algae is fairly rare at those water temperatures. Also, opening all valves so that all ports have pressure relief to the pool will virtually eliminate any chance of the pipes bursting.

But just so you know, I do practice what I preach. My situation is #3 above and I have not bothered to use automated freeze protection for 8 winters now without incident. But I do not have any plumbing less than 2".

Edit - Before reading this article, you may want to first familiarize yourself with this Pool School article on Pump Basics

Hydraulics 101 - Pump Head Curves, Plumbing Head Curves and Operating Points

Hydraulic Head

In fluid dynamics, head is a concept that relates the energy in an incompressible fluid to the height of an equivalent static column of that fluid. From Bernoulli's Principle, the total energy at a given point in a fluid is the energy associated with the movement of the fluid, plus energy from pressure in the fluid, plus energy from the height of the fluid relative to an arbitrary datum. Head is expressed in units of height such as meters or feet. - Wikipedia

Click to expand...

Hydraulic Head is a term that originated in the water distribution industry and relates to the "head" or top of the water level. It is also another way of expressing the amount of pressure (PSI=pounds per square inch) lost or gained in a plumbing system. For example, a pool pump adds head or pressure to the plumbing system while the friction loss in piping and equipment removes head or decreases pressure in system. In addition, there are two basic types of head loss and gain in any plumbing system; Static Head and Dynamic Head.

Static head is the net elevation change of the water which can be either positive or negative and is directly related to the height of the water. So water moving from a higher elevation to a lower elevation has head gain while water moving from a lower elevation to a higher elevation has head loss. For example, a pool solar system installed on a roof and where the panels/pipes are primed and completely filled with water, there is static head loss when the water rises to the roof but then there is also static head gain when the water falls back to the ground. The static head loss on the way up is directly offset by the static head gain on the way down so there is no net static head change due to the fact that the solar is installed on the roof. However, there can be temporary static head loss or gain during the priming process where there is head loss due to the elevation lift but since the return pipe is not yet full of water, there is no static head gain to offset it.

The second component of head is dynamic head loss which is due to the friction loss of water inside of pipes, fittings and other equipment. As water travels through a pipe, the friction against the internal structures reduces pressure. A pool's plumbing system will experience dynamic head loss on both the suction side of the pump and return side of the pump since water is moving through plumbing on both sides. The faster water moves through a pipe, the more head loss there will be. A pool pump adds dynamic head gain to the plumbing system so as to create positive pressure and thus water flow through the pipes. The dynamic head loss in the pipes then reduces the pressure until the water returns to the pool where the pressure is once again at 0 PSIr (PSI relative to atmospheric pressure).

A common mistake made by some that are new to hydraulics is to assume that the head loss in plumbing is equal to the length of pipe since they both use the same units. While the dynamic head loss in plumbing is related to the length of pipe, it does not equal it. Addition factors are necessary to calculate the head loss in plumbing and can be quite challenging to accomplish.

In summary, pumps and elevation drops add head to a plumbing system while elevation rises, pipes, fittings, valves, filter, heaters, etc. subtract head from a system. For a swimming pool, the total head loss is always equal to the pump's head gain since the water is returned to the same atmospheric pressure as where it came from.


Pump Head Curves

A residential pool pump is actually made up of two separate "machines". The first machine is often called the "wet end" and this is the part that actually pumps the water and converts rotational energy into flow and pressure. The second machine is the electric motor which converts electrical energy into rotational energy and drives the wet end. Together, these two machines make up a residential pool pump.

Most manufactures of pumps include head curves in their pump manuals and/or sell sheets. The curves have two axes, Feet of Head vs. Gallons per Minute (GPM). Feet of head is used instead of PSI because a centrifugal pump will always deliver the same head for any liquid of any density while the PSI will be different for different liquids and/or densities so traditionally, manufactures have used head instead of PSI.

The head curve is useful in determining the flow rate of the pump if the head loss of the plumbing system is known. Below is an example of a head curve for the Pentair Intelliflo published by the manufacture.




The maximum head of the pump is reached when the flow rate is near zero GPM and at full RPM. This is equivalent to an equal length of open ended pipe straight up in the air. The pump will fill the pipe to the top but no water will spill out.

This particular chart also shows that the energy use of a pump is fairly linear with the flow rate. This is true for all residential pool pumps. The higher the flow rate of the pump, the more energy that is used. However, flow rates tend to increase faster than the energy use which is why the energy factor of the pump as measured as gallons per Watt-hr, increases with increasing flow rate effectively reducing the energy consumption. However, there is a flow rate limit that a pump can produce which is called "run out" but most pool installations will never reach this limit because there is always at least some plumbing head loss.


Pump Speed

Typically, a single speed pump will operate at around 3450 RPM. But there can be significant advantages when running at lower RPM. The pump affinity equations can be used to determine how a pump's characteristics (e.g. head curve) will change with speed. So if the flow rate, head or hydraulic HP is known for any one speed A, it can be calculated for another speed B using the following formulas.

• GPM B = GPM A * (RPM B / RPM A)
• Head B = Head A * (RPM B / RPM A) ^ 2
• Hydraulic HP B = Hydraulic HP A * (RPM B / RPM A) ^ 3

But what do these equations really tell us? For one thing, a reduction in speed has a proportional reduction in flow rate but has a much more significant reduction in the required HP required to generate that flow rate. This is the primary reason a two speed or variable speed pump can save so much energy at lower speeds.

For example, low speed of a two speed pump has about 1/2 the flow rate as high speed and the affinity equations tell us that it requires only 1/8th the power of high speed. Unfortunately, two speed motors lose about half their efficiency at low speed so the energy use is only about 1/4th of high speed but still significant.

Current generation variable speed pumps provide even more cost savings over their two speed counterparts. Plus, given the range in RPM settings, the pump can be optimized for the given pool plumbing. The flexibility of a variable speed pump ensures a maximum energy factor for nearly any operating condition. Plus, current US DOE regulations pretty much dictate the exclusive use of VS pumps. Larger single speed and two speed pumps (>0.711 HHP) can no longer be manufactured in the US with few exceptions.


Plumbing Head Curves

Much like a pump, a plumbing system also has a head curve which is usual identified as a "Plumbing Curve" or a "System Curve". And much like a pump's head curve, the plumbing curve is parabolic in shape and when plotted over a pump's head curve, crosses the pump's head curve at a single point which is called the "operating point". The plumbing curve of any plumbing system may be approximated by this simple formula:

Head (ft) = k * GPM^2

Where k is the plumbing curve constant that is dependent on the configuration of the plumbing system. The plumbing curve "standards" are defined as:

• Curve-A which represents fairly restrictive plumbing typical of an AG pool or an IG pool with 1.5" pipe size. k = 0.0167
• Curve-B which represents extremely high head loss conditions. Not many pools would fall in this category. k = 0.05
• Curve-C which represents less restrictive plumbing typical of pools using 2" pipe size. k = 0.0082
• Curve-D which represents less restrictive plumbing typical of pools using 2.5" pipe size. k = 0.0041
• Curve-E which represents less restrictive plumbing typical of pools using 3" pipe size. k = 0.00205

Note that these definitions of plumbing curve vs pipe size differs from that you may see from APSP or others. This because the APSP definitions are much more pessimistic than what is seen from of actual plumbing systems. The definitions shown here are based upon actual plumbing system averages from the forum. Also, more accurate representations of plumbing curves may be determined from more detailed head loss calculations.

The following chart shows an example of a pump head curve along with several plumbing curves overlayed on top. The intersection of the plumbing curve with the pump's head curve is defined as the operating point.

I'm about to embark on my first year of winterization. I have a mesh safety cover so my pool is constantly taking on water. I have a gizmo in my pool skimmer n my returns are plugged. I just need to know for those of us who freeze solid, do I have to worry about water collecting in my skimmer? My guy poured antifreeze in the skimmer box after the gizmo was put in. I texted him for guidance n he said as long as water doesn't get above the skimmer box, I'm fine. I just need to know, should I take any out. Pics of current water level.

Hello TFP community,

We had our pool built ~1 year ago. The family has really been enjoying it this past season. I have never owned a pool before, so this has all been a learning experience for me. I stubbled across this website now in an attempt to take matters into my own hands after the pool store couldn't seem to help me with water chemistry issues.

Ever since this past spring (and to date), I have been having problems with maintaining chlorine levels. According to pool store testing (and my own test strips), my chlorine levels have always eventually been going to 0. I have the SWG, which I originally thought would mean I wouldn't ever have this problem. The pool store consistently suggests that my CYA is low and I need to add more stabilizer, then shock the pool with multiple gallons of liquid chlorine, and that should allow my SWG to "catch up". I have been doing a constant dance of this process, rinse and repeat, for the past 6 months or so. After adding ~20 pounds of stabilizer over the past several months, and with my SWG set to 100%, my chlorine levels continue to go to 0 after the "shock" process normalizes. At this point, "the boss/expert" at the pool store tells me she hasn't ever seen this problem in her 20 years of taking care of pools and has no answers for me. Needless to say, I am a bit frustrated and now am looking for my own answers, which has brought me to TFP.

I ordered the TF-100 kit, have read over the pool school articles, and am eager to get this problem sorted.

The TF-100 kit came in today and I ran all the tests this evening in my kitchen. Here are the results:

• FC - 1.5ppm. It was almost completely clear after 2 drops, with a small hint of pink, but I added the third to get it 100% clear.
• CC - 0.5ppm. Same here. After adding back the 5 drops of R-0003, it was very faintly pink. I added one drop of R-0871 and it was completely clear.
• CH - Not sure I did this test correctly. The water turned red after adding the 3 drops of R-0011L, however, after 30 drops of R-0012 (which would be 750+ ppm) I still wasn't seeing the color turn blue so I just stopped. If I tried hard, it kind of seemed like it started to turn a bit purple. Maybe I should try again? The pool store tests (for what it's worth) have consistently indicated that CH was in an acceptable range, so I think I am just doing something wrong here.
• TA - 50
• CYA - <20ppm. I filled the viewing tube up all the way, it started to get a little cloudy, but I could still see the black dot at the bottom of the tube.
• PH - 7.6
• Salt - I had a hard time with this test too. I bought the Taylor test strips and thought that maybe it showed something in between 2000-3000, but it wasn't very clear to me. Again, my SWG and Intelliconnect system do not indicate a salt level issue so I am not sure this is correct. Pool store tests in the past have always showed this in acceptable range as well (~3500). I did add a bag of salt back in the summer when my SWG indicated it was getting low.
• For fun, I did the K-1000 test. Man, it is really hard to read the yellow chlorine colors on this one! My best guess was maybe 2 ppm, which I guess lines up with the earlier FC test?

Some other observations/info:

• The pool water has always looked crystal clear. Never had any green water or anything like that.
• The pump runs for 12 hours /day, 7am - 7pm.
• I thought that maybe I had a leak somewhere that was depleting my CYA, but I turned off the autofill for the past week and have not noticed the water level really changing at all. Also, salt levels have always read good, so if I had a leak I would think that would go down too.
• We haven't had much rain for the past couple months like we do in the early summer, so I don't think that is diluting my CYA.
• I last added ~3-4 lbs of stabilizer maybe 3 weeks ago. Looks like I am at nothing now.
• SWG has been at 100% since this problem started in the spring.
• I thought that maybe something was wrong with my SWG, but the pool builder came out and did a "bucket test" and tells me that it is producing as expected.
• I don't really brush the pool that often since it always looks fine, but from what I read now, it seems that I should be doing this weekly regardless? Not sure if that has contributed to this problem.
• Per the pool builder instructions, I have been cleaning the cartridge filters and SWG every ~3 months.
• Per the pool builder instructions (and pool store), I have been adding Jack's Magic Magenta Stuff sequestering agent, ~6oz weekly.

Thanks in advance for any help!

I am looking for some pool house ideas, especially roof design. The pool house will have a poured foundation basement, will be 20' deep x 24' wide. I will be using a metal roof and have not decided whether to use trusses or stick built on the roof.

Anyone have pictures to share or links to sources with pictures/plans? Has anyone built their own decorative trusses or used the Simpson decorative metal straps/hangers?

Thanks,

Hello everyone and thanks in advance for your help. I've lurked here a bit and this is one of the most helpful forums I've ever seen.

Latham Olympia 16 Fiberglass

My yard is slightly sloped. Before work began, the PB said that the long side of the pool closest to the fence would be about a foot above the ground to account for the slope. It turns out that it's about 33 inches above the ground. So now I am quite concerned. To make matters worse, it does not seem I have any recourse based on what's in my contract.

1. Was this pool even buried deep enough? Based on how much sand/dirt was build up (33 inches) and looking at the pics of the dig, it look like it's not even close to being deep enough, assuming deep enough = the height of the pool.

2. The PB says the 33" tall x 3ft of sand/dirt/fill will support the long side of the pool nearest the fence. I'm no engineer but this just doesn't see right. A landscaper said that the pool would probably crack the concrete deck within a few years. PB says my options are a turndown wall or to just let the area slope down.

I'm at a loss here. The backyard looks completely goofy with the pool this high above the yard and these gaps around the fence.

What would you do in my situation?

Finally found a pool company that will even put us on their list for next year to have a new liner installed and some other work done. The owner told us he's been warned by the liner manufacturer to expect a 30% increase in liner cost for next season.

Getting ready for a new PB build in The Woodlands, TX. I'd love feedback, so please critique the design. Can't wait to get started!

Overview:
47' x 23' Free-form Pool (no spa)
4'-5'-4' Depth Profile
12" Shelf
2 x Benches
~21k Gallons

Pentair Equipment:
IntelliFlo Pump 011028
520 Clean & Clear Plus Filter 160332
UltraTemp Heat Pump/Chiller 460958 AquaCal Variable Speed SQ150VS Heat Pump/Chiller (w/ bypass)
IntelliCenter Load Center 522041 w/ i5P Personality Kit 521909 & Wi-Fi Bridge 522475Z
IC60 SWG 521105
5 x MicroBrite Color LED Lights (all facing away from the house)

Plumbing:
2 Skimmers w/ 2.5" Pipe (each separately plumbed to the pad)
8 Returns w/ 2.5" Pipe for the long segment back to the pool
Unions for all equipment at the pad
Minimum 18" straight pipe before the SWG
Center water feature 3 x sheers & 2 x flanking Venetian bronze spouts embedded in wall
No Main Drain
No Suction Port
1/2" Injection Port for Stenner Pump (after SWG)
Jandy Neverlube Valves
Fill line controlled by sprinkler controller (as a zone)
Overflow line

Electrical:
Pentair Load Center (w/ HEPD 80 surge protection)
GFCI at pad and pavilion
Extra 2" empty conduit to pavilion
Light at equipment pad
Volt Lighting 300W landscape lighting transformer
7 x Volt Lighting hardscape lights embedded in wall

Deck:
1,100 square feet white travertine Versailles pattern
Deck and area drains w/ 4" drain pipes to street
Contrasting travertine coping
Removable hand rail

Miscellaneous:
Pentair Warrior SE Robot Cleaner
12' x 12' Pavilion w/ 2 x sconces, 2 x ceiling flood lights, 4 x can lights, ceiling fan, GFCI outlets
5 x Umbrella sleeves
Backyard faces east (pool will be mostly in the shade during the hot Texas afternoon)

It's funny to me that people on the internet act like their water is in balance and they get it dialed in easy-peasy no problem. I call bull. I bet these same people giving advice walk out to their hot tubs and their water is never balanced. If this is you admit it - your water is never balanced. Stop acting like it's elementary.

So, my postsurgery knee is still pretty swollen, and after a very active week, we decided it would be best for me to take it REALLY easy this weekend. I tell you this in explanation and a transparent bid for sympathy, so no one yells at me.
Well, the kids want to come over, and Granna never says no to that, and we need to test the water and heat the spa.
Have I mentioned that all pool maintenance is Granna's job? So Hubby gets a water sample and brings me the kit so I can do the testing sitting down. PH high, Clorine high. Not surprising.
I decide to heroically put everything away myself, and rather than carry the case, two full test vials and the sample water back, I dump both (pink/red) vials of water back into the test water. I know, probably a bad idea, but it's done.
Here's my question: how bad a thing was it? The reason I ask is that red + red made GREEN. I haven't taken chemistry since a below par high school class. (Math and physics were my jam.)
Is this something I could do again and show the grandson? (At three, he counts the drops and notes the color change when I test)
Again, before the scolding begins, please remember I'm INJURED.

Hello friends

We currently run our circulation pump 24/7. But this winter I’m thinking to reduce that a bit. For a 20k gallon pool, any suggestions on how long to run it?

I’ve reviewed the closing procedures link, shared here.
but I’m trying to figure out where we fall into the levels of closing being here in Raleigh. We’ve been in Raleigh for almost 5 years. I’m that time, we’ve had 1 big snow & ice storm. But since, it’s just dusting of snow & some cold snaps I guess. Google tells me that January is the coolest month with the avg overnight temp of 29

so where does that leave me?

I had an AGP growing up in CT & I remember the pool being sealed tight for the winter. I just assumed it’d be the same.
So, I started purchasing:
Cover - Robelle 6024-4 Superior Winter... https://www.amazon.com/dp/B010TS59LC?ref=ppx_pop_mob_ap_share
Pillow - Robelle 3748 Deluxe 4-foot x... https://www.amazon.com/dp/B00ESYOFKU?ref=ppx_pop_mob_ap_share
Even shrink wrap to seal it all up tight from the wind Winter Pool Cover Seal - for... Amazon.com : Winter Pool Cover Seal - for Above Ground Pools : Swimming Pool Covers : Patio, Lawn & Garden

Then, I went to the pool store to see if the had the skimmer cover I needed & they directed me to keep the pool open, on low - for the winter. They said to super shock it, put a cover on it & keep it running
So now I’m a bit confused.
Anyone is the Raleigh area have advice for what I should do with our weather?
In reading some here, I see some notes about checking things though the winter & I have to admit, I was hoping to have a little winter break from checking all the details of the water!

1st, I want to make sure the cover I got will work for a full close or this mild close…. I need to return it soon if it isn’t the right thing.
Any insight??

I am looking to obtain feedback on our salt water pool design along with the specs which have been provided by PB#1. (we will also have others quote the same design). Please ignore the blue lines on the design document as they have been placed there to remove the name of the PB. After considering many designs over the course of the last year, we are finally getting close to pulling the trigger.

The lap pool is 14' x 41'. We are leaning towards a sports pool with 4' water depth throughout except for a 5' water depth section in the middle of the lap pool.

The spa is a 9' vanishing edge all the way around with 8 jets.

As you will notice on the specs document, the design includes 5 LED lights, 3 bubblers, and 5 jet decks.

PB#1 utilized Jandy equipment most of the time but Hayward as well (but less often than Jandy). I don't know much about pool equipment but certainly would like to control everything (pool, spa, heater, lights, bubblers, jet decks, etc) from my phone.

There will be mounts for a volleyball net in the middle of the lap pool. We will probably just buy a portable basketball goal and slide for the kids. Thoughts on this?

Also, do I need a heat pump in addition to a heater (located near Charlotte, NC)?

Any insight/feedback that can be provided on the design and/or specs is very welcomed. Thanks in advance!

Well dig day was yesterday and we are about 1/2 done. The pool company mapped out the edges based on the plans, but they later admitted that the reference post / Datum post / king post, was in the incorrect location. This caused other measurements to be off resulting in the hole being 2 foot closer to the house then it should on the deep end side. In addition, there is a 11 ton grotto waterfall to be over the back of the deep end that was supposed to go over the now disturbed dirt. They can easily dig the extra 2 feet closer to the back fence, but the 2 feet closer to the home that was supposed to be decking is an issue, since it is now disturbed soil. The excavator guy was sure ****** at the other crew members after he noticed that something was off in the middle of the dig.

Do they need fill it back in with gravel/base? I think this is less strong then virgin soil.
Do they need to just keep the shape of the pool and then adjust the decking? I think it is not that big of a deal to have a slightly larger pool, but I know it would be extra materials.
I am concerned that I will be billed the extra excavation time, since we only have 8 hours of dig time, then ~$400 per hour after, but they sure spent a lot of time trying to figure out where the measurements went wrong.
I am looking to see if anyone has experience in this.

Starting new build soon (permit applied for on Dec. 10, start in late Jan/early Feb), would like feedback on where to add a bench on benches in the pool, any ideas on location would be appreciated.
My original thought is to have a bench going along the west side (furthest from the house) and a bench in the corner area opposite the spa (near the house). The pool is just for my wife and I to relax, not to concerned about swimming laps or sports. The depth goes from 4' - 6', overall length is approx. 23' the width in the pool area is 11'.


Some specs:
All Pentair
+/- 11,000 gals
2 VS pumps (one for water features)
led for the lights, bubblers and sheer decents
pool automation - IntelliCenter
SWCG

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service firms or pool owners, each blaming the other for the phenomenon.

From 1999 to 2003, onBalance provided several case studies to the plastering industry (performed by two respected cement labs) on white spotting (which some incorrectly name it "spot etching"). It was determined that white spotting was caused by several contributory elements, all due to improper plastering practices: too much calcium chloride added as a set accelerant; adding water to the hardening plaster surface; trowel-pressing the added water into the surface, creating porosity and micro-cracking in localized areas or spots, allowing for later water penetration deep into the plaster matrix; subsequent “rinsing” (non-aggressive leaching) of soluble plaster components (calcium hydroxide and calcium chloride) from the thus-compromised surface, and late hard troweling.

Over the course of the past year, onBalance undertook an additional project to help provide more definitive and sufficient evidence as to the cause.

A one year old spotted pool in Los Angeles was inspected by both an onBalance partner and by a pool plastering industry advocate (who incorrectly describes it as "spot etching" or "etching deterioration.") Both had produced written opinions on the pool in question, with the former implicating defective plastering workmanship and the latter implicating aggressive water chemistry.



At that point, onBalance drained the pool, and with representatives of the trade press, service members, and pool plasterers present, core sampled the pool, obtaining dozens of cores from a local area of a spotted pool wall. These samples were sent to four different cement failure-analysis laboratories for petrographic examination. Results have been obtained from Construction Technologies Laboratories (a subsidiary of the Portland Cement Association), the RJ Lee Group, Riverbend Petrographics, and Wiss, Janney, Elstner. Would these highly respected labs find consensus when independently analyzing plaster cores containing white spots from the same pool?

All four labs have now submitted reports on their analysis. Here is a summary of their findings:
1. The pool plaster contained more than 3 percent calcium chloride dehydrate, which is detrimental. (The allowable maximum is two percent, and zero for colored plaster).
2. The whitish spots were smooth to the touch, but under a microscope, the spots were shown to be porous, permeable, structurally weak and soft, with an abundance of micro-cracking and a high water-to-cement ratio.
3. The depth of the micro-cracking and porosity within the spots went as deep as 5 mm (.2 in. or 3/16th) and a diameter (width) of 15 mm (.6 in.)
4. The unaffected surface (cement paste) surrounding the spots was dense, hard, and smooth, and did not have a high water-to-cement ratio, the porosity, or the micro-cracking as found in the spots.
5. There was no evidence of aggressive water or chemical attack (relative to calcium carbonate) causing the spots. The surface surrounding the spots was not etched, but instead had been “carbonated” which provided further evidence that the surface had not been etched by aggressive water.
6. The improper adding of water during plaster finishing (troweling) causes excess porosity and micro-cracking within the spots. This in turn, provides an avenue (breach) for pool water to penetrate deeper into the plaster matrix and access soluble compounds causing continued loss of plaster material.

As indicated above, improper water chemistry did not cause the white spotting, and therefore, it should not be called "spot etching" or "etching deterioration." In fact, balanced pool water – and even water with a positive CSI value – will not stop this process from happening to a defective plaster surface. And depending on the severity of the improper plastering practices, spotting may occur within a week, but usually not until a few months down the road.

White spots have a smooth, yet porous surface. This is due to the loss of two soluble plaster components (calcium chloride and calcium hydroxide which comprise of about 15 – 20 percent of the cement) interspersed throughout the more durable materials. This results in a weakened, soft, and self-deteriorating surface. Porosity, and subsequent carbonation, creates a lighter (whiter) color in contrast to the surrounding denser and unaffected plaster surface.

While white soft spotting is somewhat visible in white plaster pools, it becomes more unsightly when the surrounding surface is off-white and slightly gray due to excess calcium chloride being added to the plaster mix. And since the spots are more porous than the surrounding plaster, it can also absorb copper or iron and become aqua or brown instead of white. Spotting is especially visible and objectionable when it occurs in dark colored plaster and colored quartz pools.

By comparison, aggressive water attacks and removes most plaster compounds from a dense and smooth surface, thereby causing a uniformly etched and roughened surface, similar to fine sandpaper, and with no significant change in color. As is known, when dark colored plaster pools are given various types of acid treatments, they do not turn white, nor do they spot.

The plastering industry has no study that proves that aggressive water causes random white spotting (or spot etching) on quality pool plaster. There seems to be little doubt that the cause of plaster spotting has been discovered, analyzed, identified and documented. See these threads: How White Pool Plaster Turns Blotchy
High CYA Levels Do Not Stain Plaster

For more information, see the following post: Being Blamed for Plaster Discolorations? Don't Get Hoodwinked
scientific-evidence-on-plaster-spotting-t57853.html
And: aggressive-water-versus-improper-pool-plastering-t51900.html
For proper plastering practices, see this post: ten-guidelines-for-quality-pool-plaster-t42957.html



For another helpful picture of white spotting, see this thread: http://www.troublefreepool.com/threads/75287-Plaster-mottling-normal?p=690714#post690714

Finally finished this project!

Folks,

*** EDIT: This is a long, long thread. So I suggest you press the "jump to latest" button top right and go back to the previous posts as you have time and desire to do
so.*** To make navigation a little easier first ~30 pages are for the house construction, rest is for the pool construction that began in Feb 2024.


This is the start of a thread that I expect will take a year or so to complete. We're finally getting to build a new house and pool exactly the way we want to. I think a little context is in order up front here since it will drive a lot of the pool decisions. My job has been to manage large construction projects around the world and we've ended up living wherever we could find something "reasonable and close". So the house and pool (if there was one) was never really designed to complement each other. Then we did a 6 year sailing adventure living mostly year-round on the boat somewhere in the Caribbean and the ocean was our pool. After that we bought a home with a pool in Florida and we love it here but need another adventure. Since joining TFP I've followed many owner build threads with great interest since I knew this would likely be part of our next adventure. That day has come. We sold our house last week and closed on our new property two weeks ago. So our next adventure will be to OB the house and pool. We really want this pool design to be integrated with the home and site not just added in as an afterthought. We are getting close to complete with the architectural design and next step will be to meet with a pool design company and and do this collaboratively with the architect. The home is on about 1/2 acre and looks out over a lake between two holes on the golf course. So it seems to make sense to put a pool behind the house that has an infinity edge that overflows to the lake. Our site is elevated a good 15' above the lake and about 200' away. Does an infinity edge sound right for this situation? And can you please comment on the pluses and minuses of an infinity edge? The pool will be covered with a screen enclosure that also encloses the patio. The back of the house faces roughly west. I'll add some photos and drawings after we get the next rendition from the architect.

Thanks.

Chris

Hi all,

I've recently bought a house with a pool and I'm now madly trying to work out how to maintain it.
I think I've added the necessary details to my signature but please let me know if I'm missing something.
Over the last few weeks after i took possession I've simply been adding 1/2 L liquid chlorine twice a week and vacuuming the pool daily based on the advice of a pool guy we had visit us.
It looks like this hasn't been sufficient and after a big storm on Friday which deposited a load of debris in the pool there is a very obvious green tinge to the pool - see photo below.

My test kit arrived yesterday, I'm in Australia so I've bought a Clear Choice Labs Total kit based on seeing it referenced in the forums here a few times.
My first test results taken just now are:
CYA - just above 30
FC - 1.5 ppm
CC - 1 ppm
pH - 7.8
TA - 100 ppm
CH - 125 ppm

Working my way through the forum here I think what i need to do is first lower the pH to 7.4 and then SLAM the pool. Am i on the right track here?


, inground

pool installed this past summer and they didn’t have the cover in until mid November pool closing company said no big deal that they have orher people that keep their pools open through November

Tonight it’s gonna get down to 30 so I’m worried about damage to the pool or the heater I have the heater on bypass but it has residual water in it of course and I have the pump set to stop running at around 7 PM

Is there anything I should do or worry about when temperatures will drop to a low of 30 tonight


I checked and pool water in heater is 48 degrees

I can say the result is way better than my generic air compressor. That’s a 15 foot tall Geiser coming out the of the skimmer. This thing blew out the main drain easily as well and made it so easy to blow out the lines. Plan to also use it to winterize my lawn sprinkler system.

What changes were made during this latest update? I do see some changes with how new content is listed. Just curious if that is the only change.