How can I keep snakes out of my pool?

Snakes hide in rocks so not sure that will work.

Install snake fencing if you can.

http://www.snake-removal.com/fencing.html

Here is how to deter snakes in general:

http://www.wildlife-removal.com/snakekeepaway.html

Be careful with baby rattlers. They do not know how to control their venom when biting and can do far more damage than an adult. I catch and relocate snakes. Call your local snake catcher to remove for you safely.

Have you tried a net when your not using it and pull tight so it can’t squeeze under it

Put "Snake Away" around the pool, or preferably around the border of your yard. This can be bought at most any home and garden center.