This might sound like a crazy question but I am trying to find out if a powerhead is actually needed. I have had my saltwater tank for close to a year now without any issues. It is a 50 gallon tank and I run 100 gallon protein skimmer and a emperor 400 mechanical filter that is designed for a 75 gallon tank. My LFS informed me that I didnt need a powerhead with the skimmer and filter but I am trying to find out from some of the vets if that is true. (we all know LFS can mislead you). I have never noticed any issues without one and am trying to find out if it is needed and if so what are the reasons and benefits?