I loved my Aqua C for the First year and then out of no where it stops skimming. So I do the usual I clean it extensively, check for blockages, let it dry out for a few days outside the tank, and I even replace the power head. But nothing will get this thing skimming anymore. I run it on a 16G Nano so yes it is overkill but I think I am going to go a little more upscale and get something to sit in my refugium instead of hanging in the main tank. The tteam at Aqua C Was great but they never did come through and offer a replacement.