Hmm, snails in general are like you guys describe, but this is a zebra nerite snail. They're different. They are a lot cleaner than most other types. Pretty much the only thing they eat is algae. I don't think it's a good idea in a small uncycled tank because there is no natural food supply... but if you add algae wafers and fend off your Betta so he can eat, and if you have a PH of at least 7.6, and if you just step up water changes a little more (Maybe do them one to two days early, though not as messy, nerites are still snails) You should be fine. But that's just my two sense.
EDIT: Hmm, I think in a 2.5 tank with just a Betta you should be doing 1 50% and 1 100% water change a week, and with the added nerite 2 50%, 1 100% a week.
Last edited by baylee767; 05-29-2011 at 02:32 AM.