Under Water Vinyl Wall Stains

[CoffeeBean]

Hi,

I have a 16 X 32 AG vinyl Doughboy. Last winter I closed with shock & Polyquat. This spring I opened to pea soup. Once I got the water cleaned up and sparkling I could see a brownish greenish stain from where the winter water line was down to the wall/bottom angle.

I converted to the BBB method this year and spent the first 2-3 weeks in shock mode trying to see if it would bleach it away in case it was algae residue. Didn't phase it. I've tried brushing, using a scrubbie, etc., but nothing takes it off. It's below the water line so using anything on the sponge just washes away as soon as I dunk it in.

Over the summer I <think> that it has faded a little. It's more mottled in appearance than it was initially. It even might have disappeared from the top of the stain line down a couple of inches.

I use Ben's kit and, once I got the chems balanced, have been able to keep the water sparkling and clean.

I have read many posts that talk of Vit C, Jack's stuff, etc., but haven't seen anything related to under water stains in a vinyl liner.

I saw some that related to metal in the water but I don't have any way of testing for that and haven't seen any metal testing equipment in local pool stores.

I do have a heater but didn't run it at all last year. I have used it this last month or so.

I'm getting ready to close for the season (live in western PA. It was 40 degrees last night) so am wondering what I can do so that it doesn't get worse over the winter.

Any help gratefully appreciated.

CoffeeBean

[doggie]

I'm curious if you have a fiberglass step section. If so, did they stain too?

[CoffeeBean]

Hi,

During the winter I didn't have any steps in the pool. I take them out when I close up. This is an AG pool but I have a surround deck.

CoffeeBean

[doggie]

I'm thinking that you've got some metal staining happening. I've seen a few threads on how to get rid of those. Do a little searching here, you'll find the answers. (sorry, I don't have time at the moment)

[mbar]

You can test to see if they are metal by crushing up some vitamin C tablest and rubbing them on the stain., or use some ph down in a sock and rub it on the stain. IF the stain goes away with either of these, then it is from metals. Let us know how you make out

[CoffeeBean]

mbar,

Will this work underwater? I'm thinking that the Vit C or whatever will be washed away immediately upon immersion. OR will enough remain to use this as a test?

[kingbud]

made this post 5/10/07:

Ahhh, the mellow, friendly vibe of the PoolForum. So nice to be back. Course, I wouldn't be here reading if there wasn't just the teensiest little problem of my own. Hmmmm.... Vitamin C tablets, eh? Wouldn't hurt to have a little stash of those around the house anyway, and they're certainly not very expensive.

So. My pool man (me) did the ascsorbic acid treatment on 5/12/07. The stain did LITERALLY vanish before my eyes. Freakish, bizarre. I was slowly working around the pool edge dropping the powder in and I happened to look up before I was even finished going around and a large area opposite was already clear! So.

But today I wanted to say this: yesterday, May 24, was the first day I did not have to dump in chlorine (bleach), ie, did not have a zero reading. (I did follow instructions and put in the amount I believed correct according to the "best guess" chart - in my case about 8 ppm.) that means it took 13 days for the pool to stabilize with respect to chlorine. Does that sound right? Everything appears to be just as happy as a clam now. All the other values are fine. I should mention that my Ph behaved perversely according to what I read here - it never went down. I do not have a good tester, but the color on a test strip indicates a strong Ph, around 7.6 or higher. Now that the chlorine has settled down I plan to go to the pool store and have a test done. I'd appreciate any comments....

I still can't believe the way that stain disappeared

PS how do I lower Ph without lowering total alkalinity? would appreciate a helpful nudge from anyone on this question...

[mbar]

Yes, it could take that long to have the chlorine stabalize. Pools are very strang They all act a little differently I had a very hard time balancing my water the first time I did the stain treatment - but I had the whole pool stained yellow, plus some really big stains on top of that. My ph was something that I had a really hard time keeping up too. As for how to lower ph without lowering the alkalinity - use muriatic acid, or ph down. THis may lower the alk slightly - but very slightly, because the only way to get rid of alkalinity is to gas it off by aerating the water, which will then raise your ph It is a really good plan if you have high alk with low ph Just use some muriatic acid (be careful with it) You can go to the bleach calc and do more calcs, and it will help you with lowering the ph. I suggest you invest in a good test kit - it will save you tons of money in the long run, and lots of trips to the pool store Feel free to ask any other questions you may have.