I am in desperate need of advice. We bought my son a ten gallon aquarium. We set it up and let it run about 10 days, went to buy the fish and was told we needed a heater (they didnt tell us that one any of our other four trips there). So we buy the heater, the thermometer, put it in and began monitoring the temperature. The temperature stayed consistant, so after about 36 hours we went to buy the fish. (Yay! We were excited!) We got a pictus catfish, 3 tiger barbs and 1 rainbow shark. Took them home, let their bags float in the aquarium about 45 minutes, released them, and enjoyed watching them the rest of the day. The next day (yesterday) we got home and my son found two of the tiger barbs dead. Last night, we lost the pictus and the other tiger barb. This morning, the rainbow was still with us but I was very surprised that he was and am not expecting to find him alive this afternoon. This was a huge disappointment for us. And even though it was a ten gallon tank, I have spent quite alot of money altogether, plus, we live in a small town so it is about a 45-50 mile drive to the pet store (yes, the superstore kind) so if you counted the gas money burned it really is expensive. What should I do next? I am so frustrated. Thanks friends in advance for any suggestions! ps....I am reading info for newbies, too.