thx guys! I'll Try to make one from a gaterade bottle and see how it goes! the guppies are doing really well for being stuck in a half gallon tank! (I have two males in one half gallon, and a preg. female in the other... What to do with the babies????????????) All of my tanks are stocked to the fullest right now because I asked petsmart If I could have some of their sick/ dieing fishies and they said "What would you want them for?" and I was like TO HELP THEM! They said fine, and sent me home with 13 bettas- only 8 of which remain :( 4 guppies, a pleco, a rainbow shark, 2 bala sharks, and there were a couple more fishies that could have used help, but i seriously had NO more room, so they are prly dead by now :( anyway, thanks for the tips, and I will now be able to make bigger ones in the future, too! :)
doggyhog, it was at walmart, and it is tetra brand. it was only $12, but it was on sale. It works really well tho! on low it keeps my half gallon tanks at about 77.5 degrees. I'll try to see If I still have the boxes with the exact names and stuff, then I'll post it on here!