A couple of days ago I came across this site and after reading threads relative to my problem, I believe I know the cause. Last night I registered, thanks for the all information posted here!
I'm in over my head, so to speak, on this problem. My pool is a 20x40 vinyl liner, it's 25 years old, cement bottom, galvanized sides. A year and a half ago I had a new liner installed due to leakage of the original installation. That liner did have some staining, in addition to the serious leakage, which the pool guys attributed to possible algae growth on the bottom side. Supposedly they treated the cement.
Fast forward to now, you can see in my photographs that the staining has returned. It's a dark brown/green color which does not scrub off. I do use a copper algicide. The water was drained and refilled within a few months of the liner installation due to some gaps in the cement and stones under the liner. The pool company did a lousy job addressing both, but it is what it is, I should have installed it myself.
I suspect these are copper stains and my only alternative is to drain some water and refill, but I'm uncertain whether I'll ever rid the liner of the stains. Regardless, I have ordered the copper test strips in order to quantify the amount. From the onset of pool ownership I had purchased the Taylor Complete kit and have maintained my pool with care utilizing 3" tablets in an injector setup. My water is always kept balanced.
Wife and I appreciate any assistance and/or advise.
Regards,
DA
I'm in over my head, so to speak, on this problem. My pool is a 20x40 vinyl liner, it's 25 years old, cement bottom, galvanized sides. A year and a half ago I had a new liner installed due to leakage of the original installation. That liner did have some staining, in addition to the serious leakage, which the pool guys attributed to possible algae growth on the bottom side. Supposedly they treated the cement.
Fast forward to now, you can see in my photographs that the staining has returned. It's a dark brown/green color which does not scrub off. I do use a copper algicide. The water was drained and refilled within a few months of the liner installation due to some gaps in the cement and stones under the liner. The pool company did a lousy job addressing both, but it is what it is, I should have installed it myself.
I suspect these are copper stains and my only alternative is to drain some water and refill, but I'm uncertain whether I'll ever rid the liner of the stains. Regardless, I have ordered the copper test strips in order to quantify the amount. From the onset of pool ownership I had purchased the Taylor Complete kit and have maintained my pool with care utilizing 3" tablets in an injector setup. My water is always kept balanced.
Wife and I appreciate any assistance and/or advise.
Regards,
DA
So you've had a few headaches early on 
but we'll try to help. As you know now, copper is a no-no in pool water. The staining can be a pain. Hopefully you no longer have such copper products adding to the overall copper level in the water. For those with plaster pools, the best way to get them off is to drain the pool and do a manual acid wash. But in your case (vinyl), you might be better to remove them with a sock full of dry acid held against each stained area for a minute or so. Rub a bit as to not keep isolated for too long. Of course this is a localized treatment process. I'm not so sure there's a better way for vinyl if it's wide-spread. You oculd check with Jack's Magic products. Just pace yourself I suppose. At some point, continue to exchange water to help lower the copper content and consider the use of a good sequestrant to prevent future staining.