canister filter accidentally left off.
So, i couldn't figure out why the water was looking cloudy. Started to look around and found the filter unplugged. Didn't think much of it and plugged it back in. Then i pulled off the top to move some things around and i noticed a smell, like rotten eggs. About a minute later one of my larger fish started going berserk, when i checked him out i noticed all the fish were at the top sucking air. Now i'm panicking, unplugged filter and turned on air pump and started a water change. Drained the water down a few inches and started filling with the outside water hose spraying it in to help agitate the water. Did that a few minutes, then decided to use the water hose to drain also. Figured I would drain with both hoses to get it down faster and get it filled with fresh faster. Then i smelled something burning, realized i never turned off the heater now its busted and there is crap from inside the heater all in the tank because the glass broke from being too hot. Now I'm completely mad, so i count to ten.... With the siphon hose I start to suck out the grit from the heater. I get the tank all filled up and treat the water and the fish calm down. Dead loss is 3 flying fox and a red tail shark. now to the filter, I pull it down and inside the canister every thing is covered in a black soot type film. the filter media rinsed off fine but the walls of the can i had to wipe with a paper towel and it still did not all come off. Put it all back together and filled and put back in service and seems to be OK. The only thing in the filter besides filter pads is ceramic rings and some of seachem's de-nitrate. My question is does this make sense? What could have built up in the filter to cause so much of a problem?