odd

Hey guys. Today I noticed the fish in my 29-gallon show tank are all acting weird. They are allay the bottom and the Pelvicachromis signatus aren't nipping any of the fish or anything. Stock: 1x Spiny peacock eel (in tank for a long time, about 8 months) 1x yellow-finned spiny eel (added last...

So today I noticed that my ac70 and my penguin 200 on my 55 were both dead. All I could think of was that maybe power went out and the filters fried. I replaced them and I is now fine. What do you think happened. The tank was without filtration for @4 hours. Any ill effect to that?