Just installed one of the 3MDQ-SC external pumps for circulation on my 90 gallon.It's rated at 90 watts and gets too hot to touch the motor housing. It's also 'not quiet'. Is this normal?
I had one on a reef sump for a few years. Same as yours, too hot to touch and by no means silent. But it sure could throw water - could have used it for a jacuzzi pump. FYI, the outer ceramic housing finally cracked, so keep an eye on it.