stained plaster

[Guest Bob]

I'm getting my new pool plastered tomorrow. Maybe it's just coincidental, but the last 3 pools I've looked at all had brown stains in the plaster, and these are in areas with relatively, soft and metal free water. One of the pools was relatively new (Disneyland California Adventures Pool), plaster had a mottled appearance. My parents pool is 30 years old an it is REALLY stained, kind of a tan color all around. Is worthwhile to just use a stain control product for the life of the pool as an insurance? They seem to use phosphoric acid and could that lead to any problems?

[Guest Brian E.]

make sure you keep a eye on the ph level after the pool is plastered and filled, it will most likely spike as you continually brush the pool to smooth it out, frequent treatments of minus are required. this will help the pool to "cure" properly

[Guest amanda]

Plaster stains can be caused by a variety of things. Even a little granular chlorine setting on the bottom of the pool will leave a mark. Most of the time if it's a small spot, you can actually sand it out with 100grit wetsandpaper and it's no big deal since most plaster pools have a pretty thick layer. Pools LOVE to be brushed. You really can't brush it too much, so keep that as a good habit to establish along with proper chemical balance and it will help avoid permanent staining.