I have a Skilter 250, but my tank has only been running for three weeks. The protein skimmer does an okay job....but it is very loud and produces tons of micro bubbles. I had to put a sponge in the unit to reduce the bubbles. It's okay for my 20 gallon tank, but I would say if your tank is any bigger, don't get it. I'm actually gonna use my tax return money and buy a "normal" protein skimmer. ON a scale of 1 to 10, I'd say it's a 5.