I posted earlier about wanting to get all the fish in my life new tanks and make room for one more, I have a betta, mom has a betta, and I'm watching a betta for a friend. Anyways I was thinking of getting 4 3G tanks but that got expensive fast plus most tanks come with bad filters, anyways I go over to my neighbor because I wanted to steal a second 2.5g bowl and I end up smoking home with a 2.5g bowl and a 5g tank. So I have 2 2.5g bowls, 1 5g tank, and 4 1g tanks. I also have 2 small filters which aren't being used because they're too strong for the 1gs and don't work in a round bowl. So what I'm thinking (since I'll be traveling to/from college come august is to set up the 5g in my dorm room and get 2 more tanks for mom's/friend's betta, and my betta(s) can use the bowls when we're at home. Would this work?
On my 10 gallon split tank, I have a filter on either side. They were sucking my bettas up to the intake, so I put a sponge on the intake of each filter. You can get cheap sponges from Petsmart or any lfs. Just cut a hold in the sponge big enough for the filter intake and you shouldn't have any more problems with the bettas getting sucked up to the filter intake. It adds another level of filtration, and it makes the filters safe for the fish. Just a suggestion.
Mystery Snails get too big at about 2.5" when full grown. I'd go for Assassin Snails and feed them frozen bloodworms two or three times a week. Or, a Nerite would work if you cultivate algae for them to eat. Just put rocks or decorations in a bowl of water. Place on a window ledge in the sun.