So, it's a ramshorn.
I say this every day it seems... If you have too many snails, you absolutely, positively, 100%, are overfeeding.
Snails only reproduce when there is enough food. If you feed your fish every day, you're overfeeding in my opinion. Fish don't eat every day in the wild. Give them 1 day without food.
Is every speck of food gone in 2 minutes? (not counting bottomfeeders)
If not, you're overfeeding.
There's only one animal that will eat snails that I reccomend, and that's the assassin snail. The best thing to do is bait them.
Drop some food in on a saucer or bowl right before lights out. In the morning, get the bowl'o'snails out and throw it away.