I have an Oceanic Biocube, which I got in February. It's a great tank, and really convenient. However, in the 5 months, one fan was defective (noisy, bad bearings), a ballast went out, the actinic bulb went out, one of the screw pegs holding the plastic light lens on broke, and the lid never fit properly. On the positive side, Rob at Oceanic is fantastic, and first got me a new ballast, then a new lid, and a new actinic bulb. I was lucky, though, because it was all under warranty. I may very well gotten a lemon lid; since I got the new one, no problems (knocking profusely on wood). Just ask all the right questions and I would definitely buy new bulbs right off the bat. Other than that, it's a great system, I've been really happy with it and it's really attractive and fits nicely in my family room. I also lubricate the fans every now and then with vaseline, keeps them quiet.
The main thing is, I got this tank for $229 brand new. If you're only going to save $100, and have no warranty, that might be risky. And you want to make sure you can see it first so the tank glass isn't scratched, the light lens isn't scuffed or foggy, and top isn't banged up.
good luck!
