Hi Mark122
I'll bet those little guys can't figure out what happened. I always feel a little sad and a little proud when I put sand in a fry tank. It means my little guys aren't little babies any more.
It might be a good idea for you remove some of the sand though. As a rule it's best to keep it between a half inch to an inch deep. Any more than that and you run the risk of having problems with anaerobic bacteria causing gas pockets to form in it.