Another Cloudy Pool after Phosphate Removal

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WhatPool

Member
Jun 18, 2023
11
Waterloo, IA
I've searched and read everything I can find on TFP about cloudy pools after phosphate removal. Yes, first lesson was "don't do that." I sort-of did it to myself, and asked the pool store what I could do because my numbers were 4000+ ppm on phosphate. ( I found TFP after my pool store visit and subsequent effects. ) So, I dumped 1 qt. of BioGuard zero phos into the skimmer. ( Probably, the second mistake I made as I will not pour anything into the skimmer again. ) Bottle says that water will cloud up, but should clear over the next two days. Well, I'm going into the fourth week of cloudy water. I started a SLAM two days ago. Yes, I understand it is a process and may take a week.

Notes about pool if they did not appear in my signature: Indoor pool, 30,000 gal, vinyl, SWG.
Latest test results:
FC = 20
CYA = 50
PH = 7.4
TA = 140
CH = 225
NaCl = 3500

I am just asking if I am going in the right direction. I am holding FC at 20 ( CYA = 50 ). My OCLT is = 1 or less.
 
WhatPool said:
My OCLT is = 1 or less.
Click to expand...
That's key there. It's close, but you did appear to pass. If you have any doubt you could do one more, but if we assume you are algae-free, then it boils down to filtration. Looks like you have a single cart filter. Have you cleaned it since adding the phosphate remover? A day or two after adding the PR the filter pressure should've increased quite a bit right?

By the way, welcome to TFP! :wave:
 
For me, I simply cannot find enough good reason for phosphate remover. The cloudy water side effect is so commonplace I think it negates any vague benefits attributed to it.

That said, I am as skeptical as they come.concerning pool water "enhancers"

Chlorine is the "additive" of my choice. It's what TFP methods are centered around.........all else is peripheral.......spend your money wisely :)
 
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Thanks. I have cleaned and swapped to a second dry filter each time I use my brush with the skimmer attachment. The filter pressure never really increased more than about 2 psi. The last time I did it, it barely changed. I'm pretty sure I do not have an algae problem or at least haven't had any issues in the past three years. This is an indoor pool. So, no issues with leaves or other debris, no rain water, and hardly any sun can get to it.

I will sweep it this afternoon and continue to maintain the SLAM FC level. It seems like I can't get the precipitated phosphate filtered out. Any suggestions on how to improve filtration or other techniques with clearing cloudy water not caused by algae?
 
Did you ask yourself how phosphate got into the water of an indoor pool?
 
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My assumption is from the fill water. I created an auto-fill system which runs for 10 minutes every day. I loose on average 1/8 - 1/4" per day, but sometimes more. I have installed heat and humidity controls in the pool house this spring to help with evaporation. Yes, I probably have a leak in one of the lights, but haven't tested or removed them to find out.

I live in a small town in Iowa, and get my water from the city which pumps it from a dolomite and limestone aquifer. So, I'm not on a private shallow well. I attached a snap shot of the city's water report, but there is nothing regarding phosphates. I may have missed it and the nitrate value includes phosphates. ( I'm an electrical engineer not a chem E. :) ) WaterReportMarch2023.jpg

Phosphate level in the pool was <2000 in 2021. Do not use the pool as much as I would like, and it has barely been used in the past six months. So, no. I do not know exactly where the phosphates are coming from.
 
After all of your additional info, the remaining cloudiness is odd. Any phosphates remover should've been used, settled, and filtered out long ago by now. No filter increases seems to confirm that too. Even though you passed the OCLT earlier, I think it's prudent you give the[ SLAM][/SLAM] a little more time to be sure. See if you can pass another Overnight Chlorine Loss Test.
 
I just swept the pool and cleaned the filter. This time, I did flush out quite a lot of white junk. There was more than what came out yesterday. So, maybe I'm getting somewhere. I am also probably due for a couple new filters. I used these two last year. Perhaps they are not filtering out the fine particles as well as a new one might.
 
I may have found the source of my phosphates. In March, I treated metal stains on my steps with BioGuard pool magnet plus. This product, like Metal Magic in the TFP article I read, contains HEDP which adds phosphates as it treats the metals. The staining on my steps was not as bad as last year where I had added three bottles of pool magnet plus. So, in the past 14 months, I have added 4 quarts to the pool.

The steps look better, but I think I learned an important connection between different chemicals and treatments. There is always a tradeoff.
 
The cartridge filter isn’t going to be as good at clearing out phosphate precipitate because it can be quite a small particulate size and easily get through the filter media. You could try to use a polymeric clarifier to see if that helps but I would only do that after you’ve completed the SLAM and your FC has returned to normal operating levels. The clarifier should be used when you have time to monitor and watch the filter. If you add it and see a 25% rise in pressure over clean pressure levels, then you’ll want to swap out and clean the filters.

If you did have a leak in your pool, then you would see certain chemical levels start to revert to the fill-water values. So salt and CH and CYA would all be decreasing over time. An indoor pool shouldn’t lose too much water to evaporation if it is properly covered and the room has adequate ventilation and humidity controls.
 

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Well, I left my sweeper hose connected to the skimmer, moved it to the deep end to try to pull more cloudy water, and let it run the past couple days. Although I am still getting some white junk out of the filter, there hasn't been any real improvement.

OCLT has been <1. Current FC is 19. Last time I added bleach to raise to 20 was four days ago.

Guessing next step is to dump it and start over. Can I dump 1/3 of it?

That should clear the 3 ft end and push it to the deep end. The cloudy water appears to be more dense. Perhaps that is an illusion as the 8 ft. end just has more of the stuff to look through.

So, my question: Dump 1/3 and refill to see if I can suck out the majority of the cloudy water from the bottom or dump all 30,000 gallons and start over?
 
You cannot drain a vinyl liner pool without risk of damage. Might be able to go down 18" or so, but more risks damage to the liner.

I would just stay at it. The phosphate stuff should filter out.
 
There could be an issue with your cartridge filter allowing fines to get through. Perhaps a damaged cartridge or an internal o-ring not sealing. A 100sf cartridge on a 30k gallon pool is very undersized. It’s fine for normal pool use, especially especially general filtration on an indoor pool, but it’s not going to clear a pool that is clouded up.

You may need to completely disassemble the internals of the filter assembly and check to make sure the cartridges are good and that everything is sealed. There’s usually an internal o-ring or two on the manifold that need to be lubricated with silicone to make a good seal.
 
Thanks, JoyfulNoise. I am working on an improved filter system. My filters are in decent shape, but will still replace them as I saw the one off-brand cartridge is not sealing as tightly to the plastic filter holder as the Pentair I have in there now.
 
WhatPool said:
Thanks, JoyfulNoise. I am working on an improved filter system. My filters are in decent shape, but will still replace them as I saw the one off-brand cartridge is not sealing as tightly to the plastic filter holder as the Pentair I have in there now.
Click to expand...

I always put a small bead of silicone lube on the top and bottom manifold/rubber seal points for my my QuadDE filter. The DE cartridges look very similar regular cartridges and, in fact, the QuadDE and Clean & Clear are basically the same the filter internally except for the media used. The bead of silicone ensures that the rubber end caps on the filter cartridges seal well against the plastic manifold.

Another option that could help would be to add a polymeric clarifier to the pool. GLB Clear Blue is a decent brand. You must be careful and only add the recommended dose and I would only use it once the FC has dropped to normal. If it works, you’ll also need to throughly rinse the cartridges right away to avoid the clarifier gumming up the paper media. It’s best to do it with an old set of cartridges you don’t care about trashing.
 
Update: Well, I've finally have a clear pool again. How did I do it? Filtration, filtration, filtration. I keep the sweeper hose down near the deep end to help pull from the bottom along with the bottom return. In addition, I connected a submersible pump to a whole house filter. I've had the pool pump and the small pump running for the past two weeks. While the small pump and filter can't compete with the pool filter in volume of water, it can filter smaller particles, and I can put exactly where i need it. I've used 30 micron and 10 micron filters with the small pump. After seven days, it was clear enough to swim in. FC is still a little over 10, but falling 0.5 to 1 each day.

Thank you for all the advice and assistance along the way. I just wanted to provide feedback that I have the pool nearly back to normal.
 
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From the sound of things it would appear that your pool filter is compromised on some way. There are many forum users with cartridge filters that have no problem clearing their pool after phosphate removal within the specified 48-hour period. It would seem that either the cartridges are bad and allowing fine particulate through or there is something not fully sealing and “dirty” water is making it past the filter media. Spending weeks filter a pool should lot have been necessary at all and my guess is that your jerry-rigged submersible pump filter was doing all the work.

Glad your pool is back to normal but I think you’re due for a new filtration system.
 
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