Whole Pool Stain, Rough Plaster at Season Open

[Lenny]

Actually, I wonder whether the mesh cover has more to do with it. I pumped my water down a good 16 inches at closing and it filled up pretty quickly this year. I even pumped a bit out at one point. And then if was full to the top again by the time I opened.

By the time I open my hardness and alk are very low. I'm thinking I'd have been better off with a solid cover that keeps the rain water from diluting the pool water. Not sure what the alk and hardness of rain water are, but I'm thinking it's not optimal

[squirrel49]

Lenny,

I've had the mesh cover since I built the pool.

1st year, no SWG running, drained 18" water and closed pool. Over the winter, water level rose, I drained again at one point in the spring, prior to open. Opened to clear water, silt, worms etc on bottom. Vacuumed, shocked, balanced water, everything was great, plaster was clean and smooth.

2nd year, SWG operational, drained 18" water and closed pool. Over the winter water level rose, I drained again at one point in the spring, prior to open. Opened to clear water, silt, worms etc on bottom. Vacuumed, shocked, balanced water, but this time everything was not so great. Extremely rough pool walls and bottom with the horizontal surfaces tan/stained in color. To date, nothing has been successful in removing.

My in season water balancing, closing, and opening procedures did not change at all. I am not convinved that the SWG and saltwater pool had anything to do with my problem, but it is the only change I am aware of, so it at least makes me curious.

Pat.

[waterbear]

The difference might be that you did not keep close watch on your pH once you installed the SWG. They have a tendency to cause pH to rise and if you let that happen you could create scaling conditons.

[squirrel49]

During the season I keep a very close watch on my Ph (test daily using Ben's kit) and usually end up adding muratic acid weekly to keep within range.

Ph was 7.4 when I closed last fall. When opened this spring, PH was extremely high (>8.5). I'm not sure what happened over the winter or if Ph rise during the non-operational Winter period is normal or not.

[Lenny]

Same with me. I was all over the PH during the season but it was sky high both times I've opened so far. And Hardness and Alk very low.

I'm still hoping my problem is scaling. But I'm worried that the water pulled calcium from the plaster.

[thomas_CT]

squirrel49. have you heard of a product called hydroquest 100? I read about it but haven't tried it, maybe someone that has can chime in. It's certainly a better alternative than acid wash, imho. And if this application doesn't help your stain problem maybe Ascorbic Acid Powder can. "jus my .02 cents."

[Lenny]

Well, I took a closer look at my steps today. I tried some crushed vitamin C to see what that did to the stains. Not much. But now I believe I have it figured out.

I can see that it's a rough surface on top of the plaster rather than the plaster being pitted. I believe the stains are just scale encapsulated dirt. Does that make sense?

I used a pumice stone and it does work but it's slow and I'd go through an enormous amount of pumice. I'm going to try wet sand paper and see how that goes. Does anyone have recommendations on what would work best for this?

I'm still not sure why this happened and why it's so extensive. It's mostly on the horizontal surfaces. I know that the hardness was low when I opened. Before I closed, the hardness was low and I added a reasonable amount of powder to get the hardness within range. I may have added some after the pump was off and circulated the water with a sump pump and long hose. Is it possible that the calcium not being circulated enough could have caused a problem?

Does anyone know anything about this hydroquest 100? I love to find something that would help reduce the manual work I have ahead of my trying to sand this stuff down.

Thanks,
Lenny