Ok so here goes... I have an eheim wet/dry filter, a tetra-tec hang on filter, a protein skimmer, and an under gravel filter set up in my 75 gallon aquarium. Here's the problem I purchase two RIO PLUS 1100 powerheads to place on my under gravel filter. I placed the powerheads in the tank, one on each end and then connected them. They began blowuing the water around beautifully, for the first 5 minutes. When I went back in to adjust the direction I wantwed to water to flow, one by one the both stopped working as I was adjusting them. They won't work at all, and they are brand new!.. I don't understand, what did I do wrong? Any ideas or suggestions would be greatly appreciated. Its my first time dealing with powerheads. The both stopped functionling as I adjusted the direction I wanted the water to flow in, I did nothing more.. PLEASE HELP!