do you have any accessto used tank water, filter media, decorations,substrate, or aquarium plants? I always start my new aquariums by using as much used stuff as possible. Believe me! I started like 6 of my 7 tanks that way,lol, I always do that to cycle quick fast in a hurry,lol, and I don't think I've waited over a week each time, with no casualties. Also think of something like ramshorns bladder snails, ghost shrimp, as I have a two gallon (roundabouts) old rubbermaid drawer that I put in the backyard for the sole purpose of putting my excess duckweed in, and I guess a bladder snail made it in there. I haven't fed them crap, and for the love of god, the only water I top it off with is dirty nasty aquarium water, and they are friggin thriving way better than the ones in my tanks,lol, Yes they are breeding good in my tanks and all, but when I looked at the sides of the drawer about 3 wks after putting it outside, there are a kajillion of them crawling up the sides!!! I thought I had a high concentration in my tanks, but that thing definitely takes the cake! I don't think you can kill them!! (not to mention, you'll feel a little less guilty about putting those in there than you would if you got attached to your betta and found it dead one day. ) If you don't have any access to any thing from a well established tank from home, you can ask your lfs or pet store for some filter media from one of their tanks, and ask em also if they'll give you some pest snails, as I hear they'll give you the media and pest snails for free alot of the time.