Pebble tec question
We had a pool built in 2009 and had a Pebble Tec surface installed. Yesterday I noticed a black spot on the bottom of the pool. Not sure what it was, I first tried to focus on it. Then I tried to move it with my toe....nothing. Next I ran my toe over it, and it seems to be a hole or divet or small void in the bottom of the pool. It's about 1/2" in diameter.
Has anyone ever experienced such a thing? Any ideas what might create a hole in the bottom surface of the pool? It's a salt pool.