I've had my BTA for a about a year now. It's doing great and since I bought it, it hasn't moved until about three weeks ago when I changed my lights. I was running Nova Extreme Pro 6x54w (ATI & UV) and changed them to a 2x250w(14K) Sunpod. Overall I don't see much difference, but my BTA is trying to move up. Does that mean that it needs more light? I would think that the Sunpod is more powerful.