I had my Betta for about 4 weeks, he was beautiful! I changed his tank from a Betta tank to a 10 gallon (I was going to divide and add another one) and I added a mini heater to keep the temp right...I added the necessary chemicals to remove harmful things from the water as directed by the bottle and I also rinsed all the new accessories for the tank. He was happy! I left on vacation and left my friend in charge to watch him. Four days later he died. Now, I am not sure if I did something wrong, or if she did something wrong while I was away (I was gone for a week and he had fresh water etc the day I left) but I want to know if someone can think of anything I may have done wrong. When I came back there was food floating on top of the water and the water was super cloudy. My friend DID NOT over feed him, but I think he wouldn't eat, hence the food floating on the water. I want to get two new fishies, but I want to make sure this won't happen again!