New pool owner - Trying to get the numbers right

[LSU]

So we have had our pool for roughly 30 days, and are supposed to convert to salt tomorrow (Monday the 21st). I am trying to get my pool balanced correctly before we start this process, etc. We have been having a hard time getting our FC correct. We have been brushing the pool per PB instructions, and testing often. We do not have any evidence of algae or anything like that at all, the water has been crystal clear. I want to post my numbers from yesterday evening, and then the ones from testing this morning. My FC was at zero, and since we have been having such a hard time with it and putting in 12.5% bleach many times to try and get that number up, I told my wife to put in a larger amount this time. Our pool is in direct sunlight for 95% of the day, so I figured since my CYA numbers were off a few times that the smaller amounts of chlorine were just getting eaten up by the sun and high temps we have been having here in Texas. I added 4 gallons of 12.5% bleach last night because my FC was at zero. I wanted to see what that would do.

Please take a look and see what you think.

Testing on 8/19 in the evening

Testing 8/20 (this morning)


So, my pump has been on the whole time, and we have also been doing some aeration by having the waterfall on (trying to bring the pH up some so we can put in muriatic acid and bring the TA down. Notice after adding the bleach the FC is now 4.5, but the CYA has shot up by 20ppm. So now pool math is obviously telling me what's off, and it sees my CYA is higher, so not the FC number is higher as well. What is the best plan moving forward here to stabilize my numbers so I can convert to salt and get my SWG going, so maybe I can stop spending so much money on bleach? Thoughts? I appreciate the help!

 

[LSU]

The wife also said that the pool looked alot different. It was a deeper blue looking water, now she says it is much lighter, and maybe even a bit clearer. It was already clear, lol. I am stuck at work, but will be back home to look at all this this evening.

 

[ajw22]

Do an Overnight Chlorine Loss Test as it looks like you have algae brewing.

If so you need to follow the SLAM Process before you tweak other things/

Your FC falling to 0 lets algea get into the water.

 

[LSU]

Do an Overnight Chlorine Loss Test as it looks like you have algae brewing.

If so you need to follow the SLAM Process before you tweak other things/

Your FC falling to 0 lets algea get into the water.

I will do the overnight test tonight and see where we land

 

[LSU]

Do an Overnight Chlorine Loss Test as it looks like you have algae brewing.

If so you need to follow the SLAM Process before you tweak other things/

Your FC falling to 0 lets algea get into the water.

Overnight loss test done. The documentation for it says I needed to start at at least a 3.0 reading on my FC. I had a FC of 2.5 and my CC was at 0. I ran out of bleach to be able to bring that starting number to 3.0, so I just did the test with what I had. Here are this mornings results:

FC: 1.5
CC: .5

Loss of 1.0, and CC came up .5, what do you think?

 

[LSU]

I'm also wondering if my FC numbers should be kept at the higher end once I get them there, due to the pool being in direct sunlight the vast majority of the day. I was taking a look at this thread. Thoughts?

Might need to SLAM. Trying to figure it out.

Okay, I've had this pool for a couple weeks now. The previous owner used Leslie's for advice, chlorinated with Trichlor in a feeder on the equipment pad and a floater in the spa. His advice was, "If you come home and anything looks off, shock it." I found TFP before going blindly into Leslie's...

www.troublefreepool.com

 

[SJPoe]

I tend to keep my FC numbers toward the top of the recommended range. That way, if there is a sudden demand, or it's extra sunny or whatever, my FC doesn't drop below the lower end of the range and put me in the danger area for Algae etc.

Given that you can safely swim in anything up to the SLAM level (as long as you can clearly see the bottom of the pool for safety reasons), there is no need to skimp on the level - your pool will use (roughly) the same amount of FC per day if you start at 10PPM as it will if you start at 5PPM, so why not give yourself that buffer ?

Looking at the numbers tho,

I added 4 gallons of 12.5% bleach last night because my FC was at zero. I wanted to see what that would do.

4 gallons of 12.5% in 22k gallons of water should raise your FC by 23ppm. If you put that in at night, and the next morning you were at 4.5, that's a significant loss...either you have significant algae or some other organic eating up the FC, some chemical residual that is doing the same, or your bleach is old/bad and effectively not adding 12.5% strength. Was this over a day or something ?

I'm confused because it doesn't seem to tie up with your OCLT...

Overnight loss test done. The documentation for it says I needed to start at at least a 3.0 reading on my FC. I had a FC of 2.5 and my CC was at 0.

So one day, you put 23PPM in the pool and 19 is gone overnight, and then the next day you have 2.5PPM and overnight loss is 1PPM.

Even so, I would plan on putting in at least 1 gallon of 12.5% LC every morning until you can dial in where your consumption is...flirting with the 1.5-2.5PPM FC range is just a recipe for a green pool.

 

[LSU]

I tend to keep my FC numbers toward the top of the recommended range. That way, if there is a sudden demand, or it's extra sunny or whatever, my FC doesn't drop below the lower end of the range and put me in the danger area for Algae etc.

Given that you can safely swim in anything up to the SLAM level (as long as you can clearly see the bottom of the pool for safety reasons), there is no need to skimp on the level - your pool will use (roughly) the same amount of FC per day if you start at 10PPM as it will if you start at 5PPM, so why not give yourself that buffer ?

Looking at the numbers tho,

4 gallons of 12.5% in 22k gallons of water should raise your FC by 23ppm. If you put that in at night, and the next morning you were at 4.5, that's a significant loss...either you have significant algae or some other organic eating up the FC, some chemical residual that is doing the same, or your bleach is old/bad and effectively not adding 12.5% strength. Was this over a day or something ?

I'm confused because it doesn't seem to tie up with your OCLT...

So one day, you put 23PPM in the pool and 19 is gone overnight, and then the next day you have 2.5PPM and overnight loss is 1PPM.

Even so, I would plan on putting in at least 1 gallon of 12.5% LC every morning until you can dial in where your consumption is...flirting with the 1.5-2.5PPM FC range is just a recipe for a green pool.

We have been struggling with the FC since we had the water put in 30 days ago. I have diligently been checking for algae, etc over that time frame and we have had nothing. The water has been very clear and nothing in the skimmers. I know what pool math says it should have raised it by after putting in 4 gallons, but the numbers are what they are. I don't think we had a loss that big. Maybe those numbers are for ideal conditions? Our pool is in direct sunlight every day, and we have been having triple digit Temps for over a month now, every day. We have had the CYA number move around a bit as well, so I know that affects the FC as well. The OCLT numbers are exactly what I got overnight

The bleach has all come from the pool store, and is stored in a hot warehouse, so I dunno...maybe the strength is not as good? Either way, I am supposed to be putting in salt today and am trying to figure out if I need to actually do that. The pool is very clear this morning. From day one we have had no leaves or debris in the water, we have brushed diligently while the plaster cured, we have been cleaning the skimmer filters as well as the pump filter regularly as they catch a few rogue leaves from trees not close to the pool.

 

[ajw22]

Loss of 1.0, and CC came up .5, what do you think?

I think you should do the SLAM Process

Your struggle with FC comes from algae and not from the sunlight.

Your FC for your CYA has been too low.

The sun can consumer 4ppm of FC in a day under the Texas Sun. If you don't begin the day with sufficient FC to not fall below the minimum FC before you add FC you will get algae.

In your environment it is easy to get algae while following the startup guide chemistry unless you are testing and adding FC 2 or 3 times a day.

 

[SJPoe]

stored in a hot warehouse, so I dunno...maybe the strength is not as good?

Depends on the age, and the heat, but a hot warehouse is NOT a good place to store liquid chlorine.

The bleach should have a date code on it, which will give you an idea of age. Heat is harder to gauge, but for sure, if it's old and stored in hot place, your LC concentration could be all over the place, which wouldn't help the consistency of your numbers. A month at 90F will make your 12% roughly 8%...a month at 100 and it's barely half strength. I saw '10% shock' in a local store, on a pallet in direct sun, and the date code was a year old...at that point it was probably salty water...they still wanted $4/gal for it...

Bleach breakdown by Heat/Time

If you can, measure your FC, then immediately add a known amount of your LC (like enough to raise FC by 10ppm) and measure again about an hour later. That is quick enough to avoid any major losses from algae etc, but long enough that everything is mixing up. Pool Math should give you what it should be, your test will tell you what IS, and then you can estimate your LC quality. I'd do this before starting a SLAM, because consistency of FC levels, and the quantities required would be complicated by weak or degraded LC.

CYA shouldn't move around much unless you are adding something with stabilizer, or struggling with a consistent test. The subjective measure of that test can be challenging, so I'd err on the upper side of your tests, but you should be able to estimate where the CYA should be based on what went into the pool after it was filled. LC on it's own will not change the CYA levels.

 

[LSU]

Depends on the age, and the heat, but a hot warehouse is NOT a good place to store liquid chlorine.

The bleach should have a date code on it, which will give you an idea of age. Heat is harder to gauge, but for sure, if it's old and stored in hot place, your LC concentration could be all over the place, which wouldn't help the consistency of your numbers. A month at 90F will make your 12% roughly 8%...a month at 100 and it's barely half strength. I saw '10% shock' in a local store, on a pallet in direct sun, and the date code was a year old...at that point it was probably salty water...they still wanted $4/gal for it...

Bleach breakdown by Heat/Time

If you can, measure your FC, then immediately add a known amount of your LC (like enough to raise FC by 10ppm) and measure again about an hour later. That is quick enough to avoid any major losses from algae etc, but long enough that everything is mixing up. Pool Math should give you what it should be, your test will tell you what IS, and then you can estimate your LC quality. I'd do this before starting a SLAM, because consistency of FC levels, and the quantities required would be complicated by weak or degraded LC.

CYA shouldn't move around much unless you are adding something with stabilizer, or struggling with a consistent test. The subjective measure of that test can be challenging, so I'd err on the upper side of your tests, but you should be able to estimate where the CYA should be based on what went into the pool after it was filled. LC on it's own will not change the CYA levels.

I'm guessing that's where they keep it. They have a warehouse next to their commercial sales building. I'm stuck with what I have. I will just go buy a load of it and start the process and see where I land. It's becoming very expensive and I am ready to get my SWG going.

 

[LSU]

Depends on the age, and the heat, but a hot warehouse is NOT a good place to store liquid chlorine.

The bleach should have a date code on it, which will give you an idea of age. Heat is harder to gauge, but for sure, if it's old and stored in hot place, your LC concentration could be all over the place, which wouldn't help the consistency of your numbers. A month at 90F will make your 12% roughly 8%...a month at 100 and it's barely half strength. I saw '10% shock' in a local store, on a pallet in direct sun, and the date code was a year old...at that point it was probably salty water...they still wanted $4/gal for it...

Bleach breakdown by Heat/Time

If you can, measure your FC, then immediately add a known amount of your LC (like enough to raise FC by 10ppm) and measure again about an hour later. That is quick enough to avoid any major losses from algae etc, but long enough that everything is mixing up. Pool Math should give you what it should be, your test will tell you what IS, and then you can estimate your LC quality. I'd do this before starting a SLAM, because consistency of FC levels, and the quantities required would be complicated by weak or degraded LC.

CYA shouldn't move around much unless you are adding something with stabilizer, or struggling with a consistent test. The subjective measure of that test can be challenging, so I'd err on the upper side of your tests, but you should be able to estimate where the CYA should be based on what went into the pool after it was filled. LC on it's own will not change the CYA levels.

I will definitely go grab some and give all this a shot and see where we land

 

[JJ_Tex]

Good luck. As others have said, your FC was too low. Make sure you are following the FC/CYA chart. For your CYA of 50 your range should be 6-8 and never ever ever below FC of 4.

 

[LSU]

Good luck. As others have said, your FC was too low. Make sure you are following the FC/CYA chart. For your CYA of 50 your range should be 6-8 and never ever ever below FC of 4.

Gotcha

 

[LSU]

After I start adding LC how often can I run the chlorine drop test to see where I am?

 

[JJ_Tex]

30 minutes with the pump running is the standard answer for chemical additions. With liquid chlorine, you can probably do it sooner if needed.

 

[SJPoe]

30 minutes with the pump running is the standard answer for chemical additions. With liquid chlorine, you can probably do it sooner if needed.

I also try to be consistent with how and where I take my water sample from - it shouldn't matter too much, but why add additional variables?
I use a PVC 'straw' to grab a sample from about 2 feet below the surface, right next to the deep end steps (a length of 1/2" PVC pipe, capped at both ends with a 1/4" hole drilled in - plunge in, let it fill, cover the top hole, lift out, point at a cup or something, remove thumb, water now flows into the cup...ready for tests to be performed).

As I always sample from that same spot, I know that circulation or anything isn't messing up my day-to-day trends etc.

 

[LSU]

Okay, started SLAM. Bought some LC from a different pool supply, one that had them inside the building. Took readings on everything before I started. My FC was at 1ppm. I added 4 gallons of LC and retested an hour or so later just to see where we were at. Bingo. Good number to hold! I will retest every hour for the next few hours, and then to the OCLT tonight, and retest in the morning.

 

[LSU]

It looks like the product I was getting earlier was seriously degraded.

 

[SJPoe]

It looks like the product I was getting earlier was seriously degraded.

Could well be the case. Sometimes its the simplest solutions

Keep us posted !!