Firstly, I've got two goldfish in a 10 gallon tank. They used to be happy fishies who swam around the tank, rushed to the top when it was feeding time, behaved nicely and followed each other around. Now, both fishies are very sluggish. They hang around the bottom, float more than swim, and don't get excited when it's feeding time anymore. I've got a filter, I keep up with the cleaning, and my thermometer reads around 74F. I feed them once daily, a couple pinches of "Hikari Wheat-Germ" goldfish pellets. Is the tank too hot for them? Are they getting underfed or overfed? Any advice would be greatly appreciated and I apologize if this is in the wrong forum!