Haha, the Mini M is 5.5 gallons. I'm going to start on the Deep Blue here soon also.
I want to use the aquaticmagic outlfow because of the angle of the pipe. I need a 9mm outflow with my eheim 2213. I'm not a big fan of the gush, the do aqua has a bad angle on it. The ada one is nice, but I want to buy 2 and i'm not spending that kind of money on glass. The Aquaticmagic has a nice upward angle to it. It should fit my tubing and put out good flow direction.