1) Henry almost DIED last night. My heater shorted out for no discernable reason, and when I woke up in the middle of the night, a cold front had come in the night, and the tank was way cold, and he was listless, barely swimming. I did my best to warm the tank up, and got a replacement heater today. I got a 50w heater for a 5 gallon tank. It has a switch that tells it what temperature it should be at. I put it at 80. Is this ok? Why did my heater short out like that? will it happen again? It is an Aquean 50w submersible. Good? Bad?
2) Is it bad to leave the fish in the tank when you do a water change? I did one a few days ago, and what I did was put Prime in the water he was currently in, drew a bucket of water and then treated it with Prime. I let the tank filter the Prime through, and the bucket sit, for an hour. Then I unplugged everything, cleaned the filter, the filter baffle, etc. Finally, I got a gravel vac and vacuumed out 50% of the water.I wiped down the sides, the top, etc. Then I ran plain tap water through the gravel vac and dumped out the bad water. Then I got the bucket full of the replacement water, reversed the gravel vac, and slowly, over a period of 30 minutes, pumped water back into the tank until it was back full up. Could that have killed the heater? Could that also have contributed to Henry's near death experience? Should I just relax and not worry about killing my new best buddy?