My betta fish’s tank had a pond snail infestation, same shtick.
And my betta fish took break delight in ripping the small snails from the glass so they flipped upside down on the sand and feasted.
A couple months later there weren’t any pond snails left.
Gave him a nerite companion to keep the tank clean and he was unbelievably frustrated when the snail was too big to pluck off the glass. They’ve been together for a year and the betta just ignores Mr.Snail
So if you did get asexual reducing snails, lack of over feeding and the literal predator of your tank should do pretty good to keep the numbers low~
In my experience, nerites are by far the most effective in algae control. I like to get 1 per 5 gallons and they go to town.
One time I had a 5 gallon tank go without a snail for a couple weeks and it became just an insane wall of green- dropped 4 nerites in there and three days later the tank was spotless. Removed three of the snails and the single leftover snail has been more than enough since.