So, we have used powerheads (Hydor) that have been having problems with shocking us in and out of the tank. We have obviously removed them due to the fact that we have fish in the tank, but does anyone have any advice? It's not just one powerhead, it's pretty much all of them... we have two large ones and two small. Our tank has been without them for a few days now because we have been trying to figure out what's going on with them. Will it hurt the tank?