I would suggest looking for a fixture that will take either 2 or 4 96 watt power compacts. I myself have a 29G tank with 2 65W power compacts bulbs. Try something more like this 4 96 watt unit... http://www.marinedepot.com/md_viewItem. ... uct=CL2321 ... or this 4 65 watt unit ...
I guess you could call the sun coral the hitchhiker but the clam was definately an added bonus.
I believe it is a filter feeder, it never opens more than maybe 1/2 inch.
It is about the size of my fist.
Thanks
Justin