Whole Pool Stain, Rough Plaster at Season Open

[Lenny]

Mary, I'm in Wilmington, DE.

That's the thing that bugs me about this. We don't know how it happened and we have no idea how to prevent it. When I closed my pool for the first time in 2005 my plaster hadn't cured yet (pool was built late in the season) so I wasn't surprised my PH was high at the start of my first full season. The plaster was pretty smooth at that time though. I would have expected my PH to have been somewhat better when I took off the cover this year but it was sky high.

What king of cover do you guys have? I have a mesh cover and I'm still wondering whether that can be a negative because it's exposed to the elements. My hardness was very low as well. I had to pump a lot of water out this year due to winter rain, so the the mesh cover caused the water to get quite diluted.

[mbar]

I have a mesh cover as well. There was so much rain this year - I'm sure I had almost all new water It just shocked me that my ph was high this year, when it usually is so low when I open.

[squirrel49]

Marie: I live in Southeast Michigan.

Mary: Yes I am acid washing and sanding myself. Shouldn't be too bad. Looks like I'm postponing another week. The water haulers are backed up at least a week and I want to re-fill as soon as I'm finished (don't want to leave the pool empty for a week).

Lenny: I have very similar situation to you. I completed building my pool late summer 2005 and opened on Labor day weekend. I closed that fall and had no issues on the subsequent open. I have a Merlin mesh cover.

Picture of clean plaster prior to the problems:

[mbar]

What a beautiful pool! Hope all goes well Let us know how it turns out.

[Lenny]

Great looking pool, Pat.

After you do this, please let us know some details when you have a chance. I'm wondering about the materials and procedure in case I have to do it next year.

It really concerns me that we took the time to close like we're supposed to and still had problems.

Thanks.

[MaryS]

Lenny,

My pool was completed Memorial Day weekend, 2005. The pool company had me keep it open until November so that the plaster could cure. When the pool was opened in April 2006, the opening PH was 8.4, but no problems with the plaster - very nice and smooth. I maintained the water chemistry over the summer last year. The PH keep drifting up, but I expected that with the Salt Water Chlorinator. I just added acid every week to keep it within the range. Pool was closed Oct 2006 and reopened early April this year. Opening PH was 8.2 this year with loads of scale. We do not have a mesh cover. The cover is solid. Still not sure what caused the problem and what I should do.

Pat,
What a beautiful pool you have! Tell me, what is the procedure for acid washing? How hard is it to do?

Mary

[MaryS]

Pat,
Now that I have looked more carefully at your photo, I think we used the same pool tile. Great taste! ;-)

Again, good luck and keep us posted!

Mary

[PoolNewbie2006]

I have the same problem here in SoCal where the water is very hard in my area. I went into the water for the first time and was disappointed with the amount of roughness on the horizontal surfaces. I used my fingernail to scrape off a few of the rough spots and it was a combination of white and sandy (dirt covered scale) deposits. I had feared the worst because my SWG cell was heavily covered in white scale and not producing chlorine.

Anyhow, I want to try the method Waterbear has suggested in lowering the pH down to around 7.0 and brushing but have a few questions. No matter how much muriatic acid I add, it always seems to run high, ~7.8. That being said, I've been told not too add more than about 1/3 of a gallon of acid per day. At that rate, it will take forever to lower the pH. So...:

1) Is it safe to add more than 1/3 gallon at a time?
2) How long is it safe to keep the pH at that acidity level?
3) Are metal brushes generally safe on plaster?

Thanks in advance.

[Lenny]

Hey PoolNewbie2006,

Wow. I can't imagine why you need so much acid. How big is your pool? You might have a problem with your test method. I'd look for verification of that. Make sure your acid is a good strength as well. Yours might be 14% or even less. I'll bet one of these things is your problem.

I would add more than 1/3 gallon if I had to. Just do it slowly in front of the return. It's getting diluted quickly.

I've been using a metal brush. It honestly hasn't done much more than the nylon one so far. It certainly can't hurt.

[waterbear]

If your plaster is fully cured a metal brush will not hurt it. In fact, on fully cured plaster a combo brush of stainles steel and plastic bristles is what you should be using for normal brushing.
As far as adding acid. I would add it a pint at a time for each 10000 gallons, wait about 30 minutes with the pump running, test your pH, and repeat until your pH is where you want it.