Stained Vinyl Liner

[Cpagasky]

The Chlorine levels have been staying consistent with only 1 ppm lost last night. So it seems that I've eliminated the algae but there is still a small amount of stain remaining. Any ideas?

[PoolDoc]

Hold the chlorine up for at least 2 more days. You want to be sure the algae is completely gone, not just mostly gone.

Meanwhile, we need to see about your total alkalinity. It would be easiest to manage both your alkalinity and your chlorine if you have a Taylor K2006 or one of the few other complete kits with FAS-DPD testing. If you don't there's an Amazon link for the Taylor in my signature.

How did you get the 185ppm reading? (I'm asking, because I don't know how much to trust it.) If it's reliable, you need to try to hold your pH in the 7.0 - 7.2 range.

[Cpagasky]

I'm using the HTH 6 way test kit to test my alkalinity. I have one of the simpler taylor kits that I've used for chlorine along with some of the less reliable strips to test at the top levels. I need to order the better taylor kits but haven't done it yet.

As for my original problem, I'm thinking that I had an underlying stain that was compounded with algea, as I've kept the Chlorine levels in the shock mode all week and there remains a yellowish brown stain but the chlorine levels are no longer dropping overnight like they had originally.

Let me know if I should go ahead and get the taylor kit now, I was hoping to limp through with this one but at this point I'll get it if necessary.

[Cpagasky]

Thanks for the reply Yeggim, I went ahead and ordered the k-2006 this morning.

[aylad]

You won't regret it--it will make keeping a clear pool SSOOOO much easier!

Janet

[Cpagasky]

Here are my latest readings after getting my new test kit.
Cl - 11
pH - 7.4
Alk - 140
Cyn - 100
Calc Hardness - 250

My water is crystal clear but I'm still having the staining issue. It doesn't seem to be as profound as it was before I increased the Chlorine to shock levels, but it is still noticeable. It appears to be a light brown and its mostly concentrated around the edges of the pool and primarily on the far end opposite the filter at the top of the slope in the deep end.

Let me know if anyone has any ideas.

Thanks

[TomC]

I know this is just stating the obvious, but here goes.....Make sure that in addition to chemically attacking that algae, you are physically attacking it too. Get out the brush attachment for your skimmer pole and every morning brush the liner areas where the algae thrives. My apologies if you are already doing this.

Tom

[Cpagasky]

No problem Tom, I have been brushing it and I'm leaning back toward my initial thoughts of this being a stain as opposed to algae. I had kept the pool at chlorine shock levels for seven days and the levels have remained since. I think there may have been some algae originally as I had some issues getting my chlorine correct early in the year due to large amounts of rain but the stain was always hiding under it. I may just live with it through the summer and try to work on it later in the year when I can lower the chlorine levels and use some stain remover. Let me know if anyone has any better ideas. Thanks

[PoolDoc]

Stains that fade -- but do not disappear -- in *liner* pools with lots of chlorine and no algae are often a result of fungus or mold growing on the DIRT side of the liner. Pigment from the growth will leach through the liner.

There's no real fix, except replacing the liner and treating the underlying surface to prevent regrowth.

[Cpagasky]

That could very well be the case, but as I said earlier I've had these stains last year as well and when I treated with oxalic acid the stain will disappear for a short time only to return a couple days later. Would that be consistent with a fungus on the backside of the liner?