About two weeks ago I purchased three male guppies. I put them in a 3 gallon tank with a interior power filter and preformed a 25% water change about every 2 weeks. Everything seemed to be going just fine until yesterday one of them got stuck in the filter and died. Now I am starting to notice that the remaining two guppies are not eating hardly anything and one of them has been consistently hanging out at the bottom of the tank and seems to be rolling over sometimes. I've turned off the filter because I think it was too much for them to handle. The temperature in the tank hangs around 68 degrees. Is there anything I can do to help these guys out? Also do you think I should replace the guppy that died?