Hey, I have had one running in a 20 high tank I have been setting up to 'seed' my fuge when I get the big tank up for almost a month now, I is still going strong. Granted, there is no coraline growing on the tank yet as I haven't got the lighting i want at the moment.

I would say, I bought mine because I was curious, but I think a better brand power head and a SCWD would be a much better choice.