picked up mine last night, took my MP40 and 2 korellias number 4's out of my tank, plugged in the wp40 and out of the box without having to do anything it started throwing a nice wave across my 180, something the mp40 could never do unless I drained a couple inches of water out of the tank. Also the wp40 is silent i don't hear anything, only complaint is that the cord goes in the tank but oh well. I thought I would need 2 of these, one at each end to get enough flow but it seems I am getting way more flow from just this one wp40 then all three of the power heads I was using before.