Help! I have stumped every pool guy in northeast ohio

[S32Beatty]

Pool installed Aug. 2017
Saltwater - Automatic Cover - Gas Heater - Haywood Cartridge Filtration

Had pool open for about a month in 2017 Aug. 20th - End Sept.
Opened following May of 2018 and May of 2019.

From start of 2018 season, saw white powdery residue at bottom of pool. Tried many ways to remove. Was just a nuisance for awhile until started to stain liner black where it would settle it seems.
2019 same issues, I have been fighting all summer. I have had several different companies test water. All levels good. Ruled out Algae, Phosphates, Pollen, you name it. Still comes back. I have gone to socks for skimmer to reduce amount sucked into system. Pictures of what it looks like in water and after sucked by vacuum into skimmer. Very gritty, pretty odorless, and sad to say not much taste. Replaced cartridges, clean system every 2 weeks. Any help would be apprciated.

 

[mknauss]

Welcome to the forum!
Can you post a full set of test results from your own test kit? Can you let us know the pool surface type? Filling out your signature really helps.
Have you tried dropping some muriatic acid on the material to see the reaction?
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[S32Beatty]

I will test and post. Cant remember all last results but I do remember
PH 7.8
Alk 110
Chlorine was in good range but need to verify FC.
will get back to you on rest.

 

[mknauss]

Great. Pretty high TA. With that pH and any calcium in the water your SWCG is most likely shedding calcium scale pretty regularly.

 

[S32Beatty]

Just out of curiosity, would calcium scale stain liner, if so, best way to check if it is a calcium stain or remove?

Also as an FYI - when opened PH and TA were lower and still same issues

 

[mknauss]

Stain? Not really, unless it is attached to it or it has iron, copper, algae, or dirt embedded in it.

 

[S32Beatty]

whatever it is, it has stained black where it has settled.

 

[mknauss]

That's interesting. Does not show that in your pictures.

 

[mknauss]

Try looking at some of these past threads -- Black stains

 

[JamesW]

Did you try putting a drop of acid on the stuff?

Do you have an anode somewhere in the water or plumbing?

Can you post a picture of the system?

Can you remove the cartridge and take a picture of it before you clean it?

 

[S32Beatty]

Did you try putting a drop of acid on the stuff? - Have some, will try tonight. What am I looking for. I assume to see if it dissolves like scaling in generator?

Do you have an anode somewhere in the water or plumbing? - Not that I am aware of, if there is one, I was not told.

Can you post a picture of the system? Yes will tonight

Can you remove the cartridge and take a picture of it before you clean it? Yes will tonight

 

[S32Beatty]

Will send some of stains as well.

 

[Rocco]

Not sure this will help, but if you want to eliminate the possibility that it is entering the pool from the outside you can place a bucket of water next to the pool and see if any of the same substance settles in the bucket. This will tell you if the substance is originating within or outside the pool.