Copper Staining on Vinyl

[Alexzimmy87]

We have been fighting copper levels and subsequent staining to our liner all spring and are at our wits end!

It started with a misidentified stain, that we thought was algae but was actually a copper stain (thanks Leslie’s). So first we hit it with an algacide that caused the copper levels to explode and make the stains worse. So we added metal free and a culator pack but that didn’t touch it - and multiple stain removers which would remove the stains but not for long. Eventually we decided ionizer (which was old) might be contributing so we removed that and at the same time changed to cartridge filters. Still came back.

We checked the source water and it measures fine on copper.

We drained it down 1/3 and filled it. Still came back.

We drained it down 3/4 and refilled it last week. Stains are starting to come back. When we took it in to test the water after the refill the copper was at .1, which we are told is in the acceptable bounds, four days later it was at .3 (today). We are honestly at a loss.

Could it be the shock we are using or something? I’m not even sure what to ask at this point.

[Denniswiseman]

Could be the algicide
Don't use copper algaecide as the effects aren't always desirable. Use a Polyquat 60
(Any brand as long as the ingredients are "Poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride" at 60% concentration.)

[Alexzimmy87]

Ok - I’ll double check that.

Any ideas why if we did the stain remover and then drained the pool by 2/3s and the stain reappeared so quickly, even if the source water test less than a .1?

I realize there could be some copper left from the 1/3 that was left, but we tested it upon refill and it was a .1. It was only after bringing the chemicals up did we notice the stain and found it was testing at .3.

We theorized that maybe the shock we were using was having an adverse affect? (Powder power plus 73).

Filter was thoroughly cleaned prior to restarting.

When restarting the water we added alkalinity up, calcium, shock.

[Denniswiseman]

I'm afraid that I don't know what causes it
Are you sure it's copper, Leslies aren't always right. Maybe have it tested elsewhere or by a different person

[Alexzimmy87]

Pretty sure - the staining comes off with lemon juice or vitamin C. So it’s either Iron or Copper and the copper has been reading high with ups and downs.

We just have no idea how it could be reintroduced.

Anybody have any great success with a particular sequestering additive?