Also known as an acid wash, a drain and clean must be performed if algae has taken over your pool.
If your pool was not winterized properly, or if it’s been sitting stagnant for a while, it may have turned into the dreaded “black lagoon”.
If you cannot see the bottom of the pool, or simply want to brighten and whiten the pool itself, an acid wash is probably your best bet for making your pool usable and beautiful again.