Is shocking your pool once a week really necessary?

Oct 17, 2018
113
KATY/TX
I am 1.5 months into my first pool. To start I have been going to my local pool store and getting my water tested and then they tell me what I need to do which has typically been pH and Alkalinity adjustment by adding balance pak 200 or muriatic acid.
They have never told me to shock the pool.
I went to Inyopools.com to purchase a bunch of chemicals in bulk hoping it would be cheaper there than at the local store. (Where do you guys get your pool chemicals cheapest?)

Looking at their line of chemicals got me reading about shock which now I see needs to be done once a week or every other week and I have not done this at all for 1.5 months and my water looks very clear and clean. That may change in the Summer months since it is cold right now, but do I really need to shock that often? If my water tests continuously show everything in balance while adding muriatic acid, chlorine through my chlorinator, and the balance pak 100 or 200 and the water looks clear, is the shock necessary?

I read THIS site and that is a bit of math that it requires you to do, I assume there is already a website to calculate all of this for you if I do have to do this once every other week?
 
No, you never need to shock. If you maintain the proper amount of chlorine in the water you should be fine. See this - [FC/CYA][/FC/CYA]

Your thought of finding a less expensive source for chemicals is a good one. Pool stores are known for selling you numerous white bottles of pool chemicals that had mysterious names and purposes to cure whatever today's pool water testing found. Unfortunately the pool industry has evolved into sales by scare tactics, misdirection, misinformation and marketing hype. Go in to the store and tell them your TA is low and they are going to sell you baking soda in a fancy package at four times the cost of WalMart. Do they have a right to make a profit, yes - but lets be reasonable. Heck, even their definition of "low" can many times put you on a pH roller coaster that's hard to get off of. Is that lack of knowledge or a sales technique to sell you more chemicals to control your pH????

What do we propose? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. Which leads to

TFPC tenet - Never put chemistry in your pool when you do not know the outcome

For almost everything the pool store sells, there is a generic "twin" that you can get at your grocery store or big box store. Alkalinity low? you can go to the pool store and buy Alkalinity Up in a fancy bottle or you can stop by HEB and pick up baking soda.

So, to control your pool you need to know what is going on. many folks have a Saturday morning ritual, dip a bottle of water out of the pool and take it to the pool store (they give you the bottle for free). They test it and sell you what they say you need to "fix" what ails your pool. But, you will find not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, the results of their "testing" is used to convince you that you need to buy things. Why do you think that testing is free?

But, what can you do?? You need your own accurate test kit! Order a TF100 test kit. The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

While entirely optional, I also have the SpeedStir and Sample Sizer. They speed testing and accuracy.

I see yo have a ColorQ. We have had members attempt to use the ColorQ to follow our methods and almost all have abandoned its use due to inaccuracies and inconsistencies. We even had one member test the same sample of water three times in a row and ended up with three different sets of results. Here is an example of a ColorQ post: ColorQ vs TF100 and here is a review where the Color Q was used alongside a TF-100. Test Kit Comparison


You have a chlorinator that uses 3" tabs. We really are not against their use, but we are against their uncontrolled use. The pool store tells you that they are the easiest way to get chlorine in your pool. They are. But, they don't tell you (or really don't understand) that the 3" tabs also add CYA (also known as stabilizer or conditioner) to your pool. In Texas you need stabilizer, but not too much. Others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. The more CYA you have the more chlorine you need to keep in the pool to keep algae at bay.

While talking about chlorine understand, chlorine is chlorine is chlorine. The chlorine in bleach is the same chlorine in the 3" tabs and is the same chlorine that is produced by a salt water chlorine generator. They are just different methods of adding the chlorine to you pool water.

So, TFP is not "against" anything - it's "for" knowledge. The knowledge is condensed in the Pool School link at the top of every page.

How much Pool School have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

So again, welcome to TFP!!
 
You are going to LOVE the three links Tim shared with you. When you read the middle one your mouth will drop! We get our chemicals from the grocery store!!! How neat is that??? Now don't go buying everything on the list as we only say get what you need when you need it.

I am also going to share how we do our math: Pool Math If you don't like apps then you can look at the top of this page and click on PoolMath for the web based one.

I will also tell you really believe it is best to have your own test kit. Here is a link about the different ones we use and like: Pool School - Test Kits Compared

Welcome and have fun learning!

Kim:kim:
 
I'm reading the middle link now and here is the only problem for me is that it does not tell you how much to add to raise the pH a certain amount.

For example the ph Increaser I was going to buy has a little chart that says for a 15,000 gallon pool if your pH is 7.2-7.4 then add 9 ounces.

Is there any chart like that for adding borax to raise the pH or is it the same chart used?
 
I'm reading the middle link now and here is the only problem for me is that it does not tell you how much to add to raise the pH a certain amount.

For example the ph Increaser I was going to buy has a little chart that says for a 15,000 gallon pool if your pH is 7.2-7.4 then add 9 ounces.

Is there any chart like that for adding borax to raise the pH or is it the same chart used?
Unless your pool has sub 6.8 pH we generally don't mess with it. pH naturally rises from aeration, like splashing in the water.

If you look at our recommendations they are ranges, we try to keep folks from chasing a "perfect" number.

But, to calculate additions we use PoolMath
 
We’ve all been there as new pool owners, or when you take over a new pool and it has different flora and fauna let’s say. Pool stores are cute to me now, and certainly helpful if there’s a part I can’t live a 2 day shipping time without, but it’s overkill to approach every algae or spot as an invitation to sell chemicals. I don’t shock anymore for the purposes of shock, only if I’m leaving town for more than a week and I know the kid we have grab the mail will throw a pool party. If free chlorine is in line, and CYA is fine I never have had algae or anything but crystal water.
TFP has been great in perpetual support for loving stable suggestions and a doctrine of just what works.
 
Alright I've finally finished reading all 3 of those starter websites.

A question I have is about Trichlor which are the 3" chlorine tablets that I put into my chlorinator:

How to Chlorinate your pool says below:
2. Trichlor - Commonly sold as tablets or pucks that you simply put into an automatic container that passes pool water over them and they slowly dissolve - putting chlorine and CYA into your water and lowers the pH. They are incredibly convenient and incredibly insidious. The CYA that they put into your pool water doesn't get used up, and instead accumulates. Eventually the CYA level will build up to a point that renders your chlorine ineffective. Typically, everything is fine, until one day you start to develop algae and don't understand why.

Is there nothing I can do to stop the CYA from building up? Right now my CYA levels are fine and have been for the 1.5 months I've been doing this, but I have quite the large bucket of chlorine tablets and don't want to stop using them at least until they are 100% gone and then I will start using bleach. Maybe I can alternate using bleach for a month and then the tablets for a month or something.

And that kind of sucks that draining the pool is the only way to lower CYA, I live in a MUD district and heard water is a bit on the expensive end.

 

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Up here where we winterize pools, I'd say just start with bleach now and use some tabs early season as you refilled. Your location may limit your direct CYA removal to filter backwash and splashout. (Refilling due to evaporation does not affect CYA levels)

Otherwise, CYA does breakdown slowly. So if occasional use is right for you depends on the size of your trichlor supply is and how itchy you are to get rid of them.
 
Is there nothing I can do to stop the CYA from building up? Right now my CYA levels are fine and have been for the 1.5 months I've been doing this, but I have quite the large bucket of chlorine tablets and don't want to stop using them at least until they are 100% gone and then I will start using bleach. Maybe I can alternate using bleach for a month and then the tablets for a month or something.

And that kind of sucks that draining the pool is the only way to lower CYA, I live in a MUD district and heard water is a bit on the expensive end.

[/COLOR]

You don't want your CYA level to get over 30 - 50. The higher it gets the harder it will be to manage the FC levels required. The higher the CYA is, the higher you need to maintain your FC level. Study this chart --> [FC/CYA][/FC/CYA]

You can get away with CYA 50 in sunny Texas. But once your CYA hits 50 you need to switch to liquid chlorine and only use the tablets when your CYA drops to 30.

Dealing with a pool with high CYA will likely cost you more then you currently have invested in tablets.
 
:goodpost: What he said. Just use what you need to maintain the CYA, keep the bucket tightly sealed and when the CYA drops too far start using them again.

If water in your area is expensive you should consider a solar cover if you don't have one yet. Cuts down on evaporation.

.
 
For folks who live in areas that get those big torrential rain falls, and their CYA is a bit high, I like to tell them to drop their pool level an inch or so and let the rain water refill you for free! This will help dilute your CYA cost free :) This is also a good way to lower overly-high calcium too.

Maddie :flower:
 
And that kind of sucks that draining the pool is the only way to lower CYA, I live in a MUD district and heard water is a bit on the expensive end.

[/COLOR]

M,

I live in the DFW area and it costs me about $50 bucks to drain and refill a 17K pool... In my city, Bedford, if you tell the city you need to drain and refill your pool ahead of time, they will not charge you for the sewage fee...

Before making any decisions, it would be to your benefit to talk with your water supplier and find out what the actual charge would be to fill a pool.

To your original question.. I have not used a single bag of powered pool store "shock" in the past 6 years. I have a SWCG, but the principle is the same.. if you maintain your FC to CYA relationship, you will never need to shock again.

Thanks,

Jim R.
 
I inherited a sky high CYA pool and after getting an algae bloom with FC@8 I drained 1/2 and refilled. That’s the last time I had to shock. I have a SWG now, and buy bleach, muriatic acid, pool grade salt, bicarb, calcium, and cya from Home Depot. I have to add a cya/ calcium when I open up, some acid every other week. I can pretty well estimate it now. After some ridiculous test results I can’t trust LPS. I use Taylor test kits.
 
I am 1.5 months into my first pool. To start I have been going to my local pool store and getting my water tested and then they tell me what I need to do which has typically been pH and Alkalinity adjustment by adding balance pak 200 or muriatic acid.
They have never told me to shock the pool.
I went to Inyopools.com to purchase a bunch of chemicals in bulk hoping it would be cheaper there than at the local store. (Where do you guys get your pool chemicals cheapest?)

Looking at their line of chemicals got me reading about shock which now I see needs to be done once a week or every other week and I have not done this at all for 1.5 months and my water looks very clear and clean. That may change in the Summer months since it is cold right now, but do I really need to shock that often? If my water tests continuously show everything in balance while adding muriatic acid, chlorine through my chlorinator, and the balance pak 100 or 200 and the water looks clear, is the shock necessary?

I read THIS site and that is a bit of math that it requires you to do, I assume there is already a website to calculate all of this for you if I do have to do this once every other week?

I think these pool store sales people all go to the same school. I too have a brand new pool. The guy told me, once I get my pH and CYA squared away I need to shock it and then shock it monthly. In the summer months I may need to do it weekly.

Interesting read on the chlorine. Do most of you use liquid bleach? I was about to buy an $80 bucket of tabs.
 

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