I have a 150 gal with overflows in each corner. I have each return on a MAg 12's plus my 2 x 6100 with a multicontroller. My problem is that I have a bald spot in the middle of my tank and I also have sand particles that are constantly floating and I am trying to have a polished look for my water. Also I am constantly blowing sand off my rocks only for it to resettle back on my rocks. My tank has been cycling 4weeks now. Do you think I have too much flow or would you make mods? If so what would you do? Thanks... Also my Tunzes are turned completely down.