Thanks for the informational reply! I will definitely test my water as soon as I can go to the store and get some tests. The tank is 29 gallons. I got it off of Craigslist and the neon tetras came with the tank, so I didn’t just get two. I thought about getting more but they weren’t the fish I had in mind for my aquarium. They sure are cute though, I might get more. The betta fish I am a little worried about. In the past I’ve had a betta fish in a community tank and he did fine, in fact he was probably the friendliest fish in there. The betta fish I have now I haven’t seen be overly aggressive or anything but he has been hiding a lot. Do you think this means he’s unhappy? I got him yesterday, so I can bring him back still… but I would feel bad about that. Otherwise I could buy some substrate and put him in my 2.5 gallon tank.. but that is pretty small. I don’t like keeping bettas in that small of a tank. Anyway, sorry for the long post. Thanks for the reply.