I have two of these on my 6 gal one along the tank and second across the tank so together they in a form a "T" on top of the tank.
I even have one SPS coral there (used to be pink mili) it is slightly green now.
mushrooms love it, yellow polyps, GSP's, xenia, open brain ets.
http://www.jlaquatics.com/phpstore/s...t_ID=pc-al0909