One more thing concerning snails, they reproduce rapidly. I keep ramshorns for my puffers to eat and currently in the snail tank i have at least 40 egg sacks averaging 10 eggs each. Thats a 400 snails and these have been laid in the last 2 days. But i have somewhere near 100 snails producing these egg sacks so my case is a little extreme luckily i also have turtles and cichlids to help out. just remember at 10 eggs per sack you could have 1 snail making 10, 10 making 100, 100 making a 1000 if not kept in check. Some species of snail lay many more eggs per sack than this also and none my snails are bigger than a half inch.