I have the antithesis of a trouble free pool. I'm at a loss. Any help would be appreciated.

Muskogeee

Member
Apr 28, 2025
12
Daytona, FL
TL;DR
I can't for the life of me keep my FC up in my 12,000 gallon. Used to use tablets causing skyrocketing CYA. Just balanced everything best I could, and installed a SWCG rated for 25,000g, still waking up with 0 FC in the morning.

Hello TFP.

This is my first time here, but I probably should have joined a long time ago, and maybe saved myself a lot of headaches.

It's going to take a decent amount of history and details to fully describe my issues, so please bear with me.

My family and I moved into our house near Datyona, FL, with a 12,000 gallon inground plaster pool, in late 2019. The pool is screened in, but has two very large trees directly above the screen, which certainly contribute to my issues. We have well water, so I assume the original fill(s) were from the well, and the 2 subsequent refills since I've had it were also from the well, more on that later. The filter is a 36sqft Hayward DE filter. The pump used to be an older 1.0HP Hayward, but I upgraded to a 1.5HP Super II.

For the first ~3 years everything was fine. I would throw 2 tablets a week into the inline dispenser, test regularly with a Taylor K-2005, and balance as necessary.

Now, to when the issues started...

The first time the pool went totally green was a combination of equipment failure, and neglect. Around winter time, probably 2022, can't remember exactly, the old Hayward pump broke down. Now, my wife, bless her soul, told me not to worry about it right away, that her grandfather used to let their pool turn completely green over the winter, and always got it back up for summer. Unfortunately... that's exactly what I did. I put off replacing the pump right away, and let it turn into a swamp. Come spring time, I bought and plumbed in the Super II pump, and began the process of trying to get the pool back to swimmable conditions. That went about as good as you'd expect, so eventually I just drained it and refilled it, everything was "normal" again for several months.

Fast forward to fall 2023. I was hospitalized, had surgery, and was out of commission for a few months. The pool turned into a swamp once more, and when I was back on my feet, I drained and refilled it... again...

As before, things were "ok" for a couple months, but then the real problems seemed to start. I was using more and more chlorine tablets, eventually getting up to 5 a week, but I always seemed to have 0 free chlorine. I would shock with liquid chlorine, and every other type of shock you can imagine, and even with 5 tablets in the dispenser, I'd have 0 FC a couple days later. It was about this time that I learned that tablets contained CYA, which I did not know. After refilling, I added enough CYA to get to ~40ppm, and having put 5 tablets in per week, my CYA was off the charts. I'm assuming this was causing it to have extremely low effectiveness.

Fast forward once more to October 2024. We're on vacation in Nashville when hurricane Milton hits. Thankfully we didn't have much damage, but upon returning, the pool was pretty green, especially from all the rain filtering down through the trees and debris on the screen. I realized the next day that the filter wasn't turning on, and found that the breaker had tripped. I visually inspected the pump, which looked fine, turned the breaker on, and the motor immediately exploded, shooting sparks 10 feet in every direction. I thought, not that big of a deal, stuff happens, and ordered a new motor.

It took over a week to get the new motor, so I was just pouring liquid chlorine and algaecide in as much as possible and stirring it up, but it stayed pretty green. Once I installed the motor, I shocked it with like 10 gal of LC, used drop-out flocculant, let it sit another week, then vacuumed all the sludge to waste. I started running the DE filter again, changing DE several times over the course of the day, and was making progress, until... I looked out the window and noticed the water level had dropped a foot. Three of the brass lugs where the motor connects to the pump housing had pulled out, and water was just spraying everywhere. Admittedly, this was my fault, I probably overtightened them and weakened the bond. So now I had to wait for a new pump housing. I also didn't have enough room to work with the pipes glued into the select-a-flow valve, so had to order a new one of those too. Of course, between waiting for all these parts and having the time to do the work, it got green again. I shocked, flocc'd, vacc'd, and got everything back to "normal" once more. This time though, I was dosing LC instead of tablets.

After replacing ALL of this equipment, and doing all this work, I decided that I wanted to convert to saltwater, in hopes that it would be easier, and I ordered a CircuPool Edge 25. I balanced everything to the manufacturer's specs, with the exception of TA which was at 160, and installed the SWCG on Friday, 4/25.

Before turning on the SWG my levels were as follows:
FC 3
CC No discernable difference
pH 7.6
TA 160
CH 380
Salt 3500
CYA 40
Borate 25

I set the chlorine level right in the middle to see how that would go, and ran it all day Saturday, 8 hrs. Unfortunately, I was unable to test Saturday evening, but on Sunday morning, my FC was 0, and CC was barely any different. I am pretty sure it is generating chlorine, because the cell is clear and I can see gasses coming off the titanium plates. Yesterday, I ran it on boost mode for the entire 8 hours, and in the evening FC was 0, and CC again was different, but barely.

Absolutely flabbergasted as to how this was happening, I thought it HAD to be something that required super chlorination. I threw in a bag of cal-hypo AND a gallon of 10% LC last night. That should have been enough to bring the FC to at least 20+. I also wanted to bring down my TA and raise my CYA, so I added 32oz of muriatic acid and 1.5lb of CYA granules.

This morning, less than 8 hours after adding all that chlorine, my levels were:
FC 3
CC 5
pH 7.2
TA 150
CYA still ~40 but ofc it dissolves slow
others same as above.

I should also mention that I took a sample to Leslie's and, per their test, I have no phosphates, 0.1ppm iron, and 0.2ppm copper. I got one of those CuLator metal absorbing packets and stuck it in my skimmer basket.

What could possibly be going on to make the chlorine disappear so fast. The water is clear, there's no visible algae, no excess debris. How can I be sure the SWCG is working properly?

I'm really lost here.

I don't know what to try next.

Any advice would be greatly appreciated.

Thank you, and I'm sorry for rambling for so long.
 
Hi and welcome. Sorry to hear about your pool troubles but there are thousands of people here (literally) who will help you.

The first thing that jumped into my brain when mentioned inability to hold chlorine and previously high CYA was ammonia. Please read up Ammonia and see if this fits your situation.

It also might not be a bad idea to run an OCLT to see if there is any algae brewing
 
The first thing that jumped into my brain when mentioned inability to hold chlorine and previously high CYA was ammonia. Please read up Ammonia and see if this fits your situation.
CYA would be 0 with ammonia. Not ammonia.

Welcome to TFP. If you can't hold chlorine, either your cell is not working, not on high enough % output or pump run time, or you have algae...even if you can't see it.

Take the CUlator and throw it in the trash.

Edge in your pool for 8 hours and 50% would be 2FC. Since you are consuming more than that you likely have algae.

Add 5ppm of liquid chlorine, nothing else!

Do this test tonight. Link-->Overnight Chlorine Loss Test
You fail, then straight to SLAM. Link-->SLAM Process

Full House Ok GIF
 
What hit me is that you never fully got rid of all the algae, even after draining. Have you checked inside the light niches and inside any ladders for algae?

Also, you may need to run your pump/SWG longer hours, but the first thing is to run the OCLT
 
Hi and welcome. Sorry to hear about your pool troubles but there are thousands of people here (literally) who will help you.

The first thing that jumped into my brain when mentioned inability to hold chlorine and previously high CYA was ammonia. Please read up Ammonia and see if this fits your situation.

It also might not be a bad idea to run an OCLT to see if there is any algae brewing

Thank you for the reply. It doesn't seem like that since my CYA doesn't really drop, but I do have plenty of aquarium tests so I can always check. I will definitely try a more deliberate, controlled overnight loss test!
 
CYA would be 0 with ammonia. Not ammonia.

Welcome to TFP. If you can't hold chlorine, either your cell is not working, not on high enough % output or pump run time, or you have algae...even if you can't see it.

Take the CUlator and throw it in the trash.

Edge in your pool for 8 hours and 50% would be 2FC. Since you are consuming more than that you likely have algae.

Add 5ppm of liquid chlorine, nothing else!

Do this test tonight. Link-->Overnight Chlorine Loss Test
You fail, then straight to SLAM. Link-->SLAM Process

Full House Ok GIF

Thank you for the reply. I can definitely see a reaction happening in the cell, so it's doing something. Of course, I guess I can't really tell how well it's working.

I will definitely try the OCLT tonight. I'll have to wait until the weekend to SLAM it, but sounds like a plan.

CUlator no good? What else will remove the metals, or do I not even really need to worry about .1ppm and .2ppm? (If Leslie's test was accurate) :rolleyes:

Once algae has been killed off and gets trapped in the filter, is it necessary to change the DE immediately? Will dead/decaying organics in the filter cause more problems even if it's technically not time for a DE change yet?

What hit me is that you never fully got rid of all the algae, even after draining. Have you checked inside the light niches and inside any ladders for algae?

Also, you may need to run your pump/SWG longer hours, but the first thing is to run the OCLT

Thank You! I didn't even think to check behind the light, even though the one time I removed it before it did have a bunch of algae behind it. I also rarely ever use the main drain, only skimmer and cleaner, so I wonder if any is built up on the sides of that. Is it possible to actually grow and adhere to the inside of dark areas with flow?
 
CUlator no good? What else will remove the metals, or do I not even really need to worry about .1ppm and .2ppm? (If Leslie's test was accurate) :rolleyes:
Don't worry about them if you don't have stains.

Once algae has been killed off and gets trapped in the filter, is it necessary to change the DE immediately? Will dead/decaying organics in the filter cause more problems even if it's technically not time for a DE change yet?
Clean your filter, recharge DE. Note filter pressure. When pressure rises 25%, clean/backwash again. It may take several cleanings/backwashes.
 
Thank you for the reply. I can definitely see a reaction happening in the cell, so it's doing something. Of course, I guess I can't really tell how well it's working.

I will definitely try the OCLT tonight. I'll have to wait until the weekend to SLAM it, but sounds like a plan.

CUlator no good? What else will remove the metals, or do I not even really need to worry about .1ppm and .2ppm? (If Leslie's test was accurate) :rolleyes:

Once algae has been killed off and gets trapped in the filter, is it necessary to change the DE immediately? Will dead/decaying organics in the filter cause more problems even if it's technically not time for a DE change yet?



Thank You! I didn't even think to check behind the light, even though the one time I removed it before it did have a bunch of algae behind it. I also rarely ever use the main drain, only skimmer and cleaner, so I wonder if any is built up on the sides of that. Is it possible to actually grow and adhere to the inside of dark areas with flow?
If you rarely use the main drain, you should, once in a while open it to get some chlorinated water through it, as well as other things not used a lot(pressure side cleaners, deck jets, bubblers, etc.)
 
Thank You! I didn't even think to check behind the light, even though the one time I removed it before it did have a bunch of algae behind it. I also rarely ever use the main drain, only skimmer and cleaner, so I wonder if any is built up on the sides of that. Is it possible to actually grow and adhere to the inside of dark areas with flow?
Crack your main drain so you get 90% from skimmers and 10% from main drain. Run this way on an ongoing basis.

Brush inside skimmers, under main drain covers, on weir doors, outside and inside ladders, and behind removable lights if applicable.
 

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CYA would be 0 with ammonia. Not ammonia.

Welcome to TFP. If you can't hold chlorine, either your cell is not working, not on high enough % output or pump run time, or you have algae...even if you can't see it.

Take the CUlator and throw it in the trash.

Edge in your pool for 8 hours and 50% would be 2FC. Since you are consuming more than that you likely have algae.

Add 5ppm of liquid chlorine, nothing else!

Do this test tonight. Link-->Overnight Chlorine Loss Test
You fail, then straight to SLAM. Link-->SLAM Process

Full House Ok GIF

Welp, I went from ~4.4 FC to ~1.4, from ~9pm to ~6am... So I guess I'm slamming this weekend. Before that I'll check & scrub every nook & cranny, and clean out/recharge my DE filter.
 
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Do you still have the CYA granules dissolving? If so, remove them ASAP to make your SLAM easier.

Also I would recommend starting the SLAM sooner to get ahead of any visible algae and also a weekend is typically not long enough.
 
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