That is what is so troubling to me-- how quickly the fish died-- all the fish were huffing and puffing-- I thought my wrasse was a goner-- he wasn't moving at all-- just lying on a rock--but you could just see his gills moving-- but after about 10 minutes with the power converter-- he was swimming around picking at things like nothing ever happened-- Do you think it has to do with my canister filter? Besides that I have two power heads and a protein skimmer and a heater of course-- In the panic-- I just went and bought the power converter-- I didn't check the temp-- but I know it was icy-- b/c I had to get the dead fish out before it polluted the water----- It's very upsetting-- all is well now--