Perimeter Stain

[mbar]

Do you know where the copper is coming from? The reason your stain came back after the stain treatment is because you didn't put in a sequestering agent to keep the metals in suspension. If the metals go back into the water, they need the sequestering agent to hold them in the water, if there isn't enough of it, the high chlorine levels will react with the metal and they will fall out of suspension and land on the surface of the pool. I asked where the metals came from, because copper is in a lot of the chemicals you buy at the pool store now - even in a lot of trchlor pucks. If you think the metals are coming in from your fill water, then you will always have to make sure that you have enough of a sequestering agent in your water. I hope this helps, feel free to ask any questions you may have.

[Pam and Jim]

Thank you for your help.
I will check my tablets- I do use tablets in the chlorinator
I use baking soda to raise the Alk and Soda ash to raise the PH.
Shock with bleach.
I did put in a chemical called Bug out-
Will copper be listed on the bottle- or will it be listed as some other name?

Do you know if the copper could be leaching from an old hose- or somewhere in the filter- any ideas how to check them? How can I can tell if the copper is coming from our city water?

Any ideas on this will help- and thank you again.

Pam

[mbar]

I am pretty sure the copper would be on the label of "bug out" and the chlorine pucks, Other than that I don't know how to find out where the copper is coming from. I don't know where the metals come from in my pool- my water always test no metals, but I get stains, so I can't help you there. Maybe someone else knows more on finding the cause of it? But I do know that they can be controlled by keeping a sequestering agent in the water, adding the fill water through the filter, and keeping the ph on the low side. Post your chemical numbers (fc, cc, tc, alk, ph, cal,cya) and maybe I can see if anything is off.

[sartail]

Do you have a brand of sequestering agent that you recommend? How do you add fill water through the filter? (I have an above ground pool w/ sand filter.)

[mbar]

I have used metal free, sequasol & Jacks Magic. They are all good. To add the fill water through the filter, you put your hose in the skimmer (with a trichlor puck). The water will hit the puck, and flow right into the filter before it is returned to the pool, so it could help the metal stain the filter instead of the pool. The sequestering agent should keep the metal in suspension - make sure you add at least enough of what the bottle says, because more won't hurt anything, but not enough will leave some metal free to fall onto the liner.

[edarling]

I thought the sequestering agent put the metal in suspension so it can be filtered out. So, if you raise CL too soon, the metal falls on the liner and stains, but if you wait a week or so, the stuff filters out of the water. No?

[mbar]

I thought they would be filtered out too, but I am told that they do not get filtered out - they just stay in suspension. But I have had my water tested after the treatments and they test as no metals, so I don't really know. I do know that if I keep my water treated with the sequestering agent I don't get the stains back. I keep reading all I can about the metals in swimming pools, but there doesn't seem to be a way to filter the metals out, except by doing it a way that Pool Doc says - but it involves careful control of ph and bleach to get the metals to fall out on the filter. I don't have a complete understanding of it yet. If anyone out there can chime in and give a better answer, please do!