Hello John...
If you have too many snails, then you're providing too much food. Unless you have fry in the tank you don't need to feed your fish very much. Aquarium fish can easily go a couple of weeks without food. In the wild, fish are lucky to eat once a week. So, if nature doesn't feed very much, then we should follow that example.
I feed my Livebearers, including the fry, a couple of times a week and just what they'll eat in a minute or two. A tropical fish stomach is about the size of one of it's eyes, so it doesn't take much to fill it.
Next time you feed, see how much food makes it to the bottom of the tank. It should be minimal and the bottom feeders will forage for that. Control the amount you feed and I'll bet the snail population is under control within a month or two.
Just a thought.
B