Pool Stains - Algae or Metals? please advise.

Achtung

New member
Aug 19, 2018
4
Pomona
Hello,
New to this forum. I am new to pool ownership and am having issues with pools stains. I have included pics but the are hard to see clearly as they are about 7-8 feet underwater. I have tried Vitamin C test (rubbing on stains), chlorine tab test (rubbing on stains to see if they fade), and Oxalic acid in a sock and sat on a stain overnight. None of these have helped identify the type of stains my pool is suffering from. When we got the house, a pool inspector mentioned that the stains were due to "electrolysis" and that I could add a zinc metal in the skimmer to help mininize the stainings, but that they would not disappear. Over the last months, these stains have seemed to spread. I've tried the various treatments, and while they do seem to lighten the plaster, they don't do much if anything to the actual stains. I get my water tested regularly at Leslie's and my numbers are usually good and within safe range. At times my phosphates have been high, but i've managed them with Phos Free. I've use the CUlator metal remover, and there was minimal staining on that (a few light spots of yellow-iron, and a hint of blue - copper?) to indicate no metals. Leslie's testing has supported my water having little to no metals in it.
They also told me that Black algae would look like the plague, so i'm assuming it isn't black algae. I've brushed with metal brush and that hasn't removed them so I'm also assuming it's not black algae. I notice that members have indicated that using "Blue" chlorox pool items can cause staining. I have used both Chlorox Blue shock and tablets for a good chunk of the last year. I have since stopped and started using the Leslie's version of both of these. I used these originally until I switched over to the cheaper Chlorox brand.
Any advice? I don't want to keep spending money on expensive treatments that don't work. If these are stains that can't be removed without acid wash, then I guess I will wait until i am ready to swap out water. I might add that we started with fresh water when we got the house a year ago. Thanks in advance for any tips/advice!
 

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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: You might try some dry acid in a sock and hold that on a stained area for a short bit to see it that does anything (copper). Based on everything you said that would be my first concern. You can pretty-much ignore everything the pool store told you to include phosphates and water testing results. It's almost always inaccurate. You'll be better off getting your own TF-100 (link below) or Taylor K-2006C test kit. But try that dry acid test and report back to let us know if it worked.
 

Achtung

New member
Aug 19, 2018
4
Pomona
Hi, thanks for your advice. I did attempt the dry acid in a sock, but unfortunately it didn't seem to do anything. The stains are still there after a few attempts with of dry acid. Based on what I've seen on youtube videos, the stains should have disappeared or lightened considerably. This did not happen with the dry acid. I'd appreciate any other advice! I ordered the Magic Jacks stain identifier so hopefully that will help me pinpoint the cause of these stains.
 

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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Magic Jack's was a good choice. Their kit seems to have a way of ID'ing stains when regular tests don't seem to pinpoint anything. It's possible whatever was the source of the stain may be embedded in calcium as well, so that's another reason where proper test results come into play. But we'll watch for updates to see what you learn.
 

Achtung

New member
Aug 19, 2018
4
Pomona
Hi again,
I just got done using Jacks Magic Stain ID kit. Unfortunately, I wasn't able to get any conclusive results. If anything, i got new stains (yellow) after using the Safe Shock in addition to the #2 solution (Copper & Scale ). Other than a lightening of the plaster, the stains seemed to remain. It seems as though all of these chemicals lighten the plaster color but actually leave the stains behind.....any thoughts?
 

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JamesW

TFP Expert
Mar 2, 2011
20,370
I'm thinking copper and possibly silver.

Do you have a cartridge filter?

If yes, can you post a picture of the cartridge before you clean it?

Copper stains can set in and they can be very difficult to remove if not impossible.

Jack's #2 copper and scale stuff (sulfamic acid) might work but maybe not.

Even if it does work, the copper will still be in the water and you would need to replace the water to get rid of the copper.

Sulfamic acid will convert FC to CC for months.

Don't drain the pool without verifying that it's safe to do so as the pool could potentially float.

An acid wash might work but it will make the plaster very rough.

Treating copper stains can sometimes make new different stains that might be permanent.
 
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Achtung

New member
Aug 19, 2018
4
Pomona
Hi, thanks for the advice. I cleaned out my filter today and have included pictures of the filters. I am not aware of any other machines/equipment that the previous owners used. I do know that the pool itself is about 9 years old. The water is about a year old, as we had the water changed before moving in. I did not notice any weird discoloration on the filters themselves, although the runoff has a greenish/greyish tint to it. There has been a lot of wind (and leaves) so I did wash out a lot of organic debris, so maybe the greenish tint came from that? I have also pictured two filters (before and after) to give you an idea of what they look like. Thanks again!
 

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JamesW

TFP Expert
Mar 2, 2011
20,370
The runoff looks like copper.

The cartridges don't look like there's a lot of copper, but it's hard to tell for sure.