Yellow/Brownish stains in above ground pool.

[Scollops]

My pool has undergone a number of weeks of recent stain removal. Chemistry is almost balanced and crystal clear water. Stains had progressively got worse over months.







Not sure if this was Covid impact, rubbish salt, watered down chemicals, Green coloured acid to name a few.







In summary removed most stains, but this step still has areas of staining. Yellowish/brown in the corners, on the step. Also bottom of the pool is a patch.







Attached photos appreciate some thoughts- as mentioned have been cleaning, brushing and testing regularly. Just not always updating my poolmath sorry.

But I do test more recently FC at 5 now, PH 7.4 becoming steady. Using chlorine and acid and not my swg (seem to
Create more staining).

 

[Texas Splash]

In summary removed most stains, but this step still has areas of staining. Yellowish/brown in the corners, on the step. Also bottom of the pool is a patch.

We're going to need more info. How were stains removed previously? Did you confirm what type of stains you had (iron, copper, organic, etc)? We do see in your Poomath logs that your FC fell quite low several times. Were you having problems with your SWG? Also, have you done an Overnight Chlorine Loss Test recently?

 

[Scollops]

No previous stain mentioned. The pool has overtime about 6 months accumulated stains. Mainly on the pool step, bottom of walls and around jets. I just finished a stain cleaning process, which has removed quite a bit actually. Just these odd areas as shown, in terms of stains, had two companies come out and test but couldn't identify what the stains where. Even doing spot cleans etc....didn't come up. So took it on myself to pick-up poolstainremovers kit and blitz it.



personally it's a mixture of stains, hence most coming out. But this Dang step discolouration is an unknown. Think I've done metal testing and phosphates to death over the last month.

 

[Scollops]

Picture today hopefully see more of the step and patch in the pool. You can see yellowish corners and bottom of walls . Another iron check ??

 

[Texas Splash]

Another iron check ??

Yes, I would. Very easy to do and would confirm or rule out iron.

 

[Scollops]

Will do , will be annoyed if it is after this recent stain clean-up.

 

[mgtfp]

Are you using a sequestering agent to keep the metals you removed from the surfaces dissolved in the water? Otherwise the stains will return (or already have).

 

[AUSpool]

Do you have or used the magnesium salts?

 

[Scollops]

Yeah sequestrant and more recently going to use DE. I don't have or have used magnesium salt. Oddly I was looking at adding in mineral ....not convinced yet on making rhe move.

 

[mgtfp]

Yeah sequestrant and more recently going to use DE. I don't have or have used magnesium salt. Oddly I was looking at adding in mineral ....not convinced yet on making rhe move.

I don't really see a benefit in mineral (i.e. magnesium) salt. Seems to be bit of a marketing hype in Australia. Something they sell as health beneficial so they can charge more.

 

[Scollops]

Iron test with Vit C - no change. Did remove some old staining not this step and floor. Guess next is salt, chlorine ....

 

[mgtfp]

Did the stains change colour?