The thin-set helps to bond the new tiles to the appropriate substrates. It is important to remember that thin-set doesn't stick well to paints or other non porous surfaces, even if they are coated or sealed.
Pools need to be resurfaced every 8-10 years on average. You might need to consider maintenance if you observe any of the following signs.
Then, we will turn off all equipment and drop a submersible pumps into the pool to drain it.
midnight blue pool plaster