post-winter scale on replastered pool

[joeturf]

I am posting this here after possibly posting it in the wrong category...

Help! Our pool was replastered by a pool contractor in May of 2005. We followed the contractor's instructions after the work was done...balancing the water and frequent brushing all season long. During the summer, some discoloration in the plaster showed up and the contractor eliminated the discoloration in October by dropping the pH very low with slight circulation (small submerged pump) for a couple of weeks. The color faded and the pH was rebalanced by him. We double checked the pool chemistry, covered the pool the 1st week (hard cover) of November as we always did in previous years, and put it to bed for the winter.

When we opened the pool mid May, the pH was off the scale, over 8, and scale had formed over the entire plaster surface that was under water.
The contractor said he was not responsible and told us we should have gone into the winter with a lower than normal pH since the plaster was still curing. He didn't tell us that before the pool was closed up for winter. He now suggests we lower the pH (to what?) and brush the pool 2 or 3 times daily for several weeks.
Another contractor told us we would have to drain the pool, sand the plaster, acid etch the pool and refill.
Has anyone experienced this? What do we really need to do?

[imfignewton]

Go to the National Plaster Council web site and submit your questions to the plaster professionals.

/www.npconline.org/mc/page.do?sitePageId=3691

[joeturf]

Actually, I did that before your reply but I haven't heard anything back yet. I was hoping somone in the forum would have some good ideas in case they don't respond...

[joeturf]

So much for help from the National Plaster Council... no one replied. Doesn't anyone have experience with this?

[imfignewton]

Post what kind of plaster finish that you have. Is it a premix like CLI, SGM, Aquavations or is it white plaster or is it job mixed color plaster. If it is a premix post the manufactures name. I'll look into it this next week and post an answer for you. Hope I can help.

[joeturf]

Dear Imfignewton,

Thank you for your reply to my inquiry concerning my plaster scale problem. I do not have the answers to your questions, but I will get the information for you ASAP. I do know that it was a white, and not a colored plaster. Since my inquiry, I have been slowly reducing the pH to 7.4 with muriatic acid over several days and brushing the pool with a nylon brush. I have been told to use a wire brush but have not yet done so. I am having some success, but now, my calcium hardness has jumped to 600 or more. All other chemicals are in balance. Now I have pool drainage on my mind due to the calcium hardness.

Looking for information.

Joeturf