i went and bought two but i need one more....one is only good for 20gallons and i have a 55g. i hooked them up but they havent started yet. i hope they're good
My LFS has one on a 55G and the plants are going nuts. Its been on for a month and watching the difference in the plants is amazing. I plan on putting mine on a 75G so I hope it works.
I've been using the Hagen system in my 20G cory tank for about 2 months now and I'm quite pleased with it. I can reduce the application of Excel from daily to weekly/fortnightly now.