Well, as usual, i changed my mind. I am running GFO instead. I have it valved down to the point that the gfo is slightly boiling on the surface in spots. I had a brand new marineland mj400( knockoff brand) on it, and HOLY SMOKES, did that pump rattle. I couldnt listen to that thing for 5 secs. Luckily, I had an italian made cobalt mj1200 on hand. I switched to that, and silence! Hopefully its ok throttled way back. Ill just take a minute to say NEVER waste your money on the marineland maxi jets. They are horrible. I work at an aquarium, and my old boss ordered a bunch of them. They either just die and stop working, or leak voltage and trip gfi. Im not talking just one or two, but half a dozen units have failed. In the meantime, 10 yr old plus original maxijets we have are running circles around them. Get the cobalt italian made ones! Rant over.