Here's why I ask. My pool is only a couple of months old, we had to drain it
only after a couple of weeks after completion (pool was only empty over nitght)
to repair some tile. Since I filled it back up, my blue 3m plaster isn't nearly as blue as it was, the surface looks like a layer of white chalk is on it.
So today, I lowered the pool level to expose the step of the spa and poured some acid on a little area, the steps looks better than it did when it was first completed.

Now I want to acid wash the entire pool, Would the acid do any harm to 3m plaster that is so new? Would it shorten the life of the plaster? Or is there something I can add to my pool to make it real deep blue again?

Any thoughts?