Well, you know that you bought a piece-of-sh!t when the manufacturer won't even respond to emails regarding a replacement of one of their products ... I wish you hadn't bought the Aquarius II, or had at least came here to ask someone their opinions about it, because had you done so these problems would have never arisen, as you would never have purchased the worst of the worst, the Aquarius II. What size tubing does the unit use? 3/8" or 1/4" ? Measure it, because you can replace the pump with something small and non-thermaltake. DanDen's MagDrive would be a good replacemen, but you need some adapters to get it working with your tubing size. Otherwise, maybe a Via Aqua 1300 would better suit your needs, with its higher flow-rate, though larger size.
... come to think of it, if i were you i'd rebuild the entire damn thing to fit an Eheim 1250 with some 3/8" ID tubing (at least) .. mind you, that TT waterblock probbly wouldn't be able to handle the pressure, lol ... forget what i just said, get a replacement pump and pretend you got something worth the excessive price, poor performance, and now the added benefit of a dead pump and an unresponsive manufacturer.. have fun