Thanks for the great comments!
what type of lighting to you guys keep your squamosa's under? i've read that they don;t require as much light as maxima's
would a 400mh be enough if it was kept on the bottom of a 22in tall tank?
Mine is under a 400wt 10,000k Ushio (on PFO HQI ballast) and gets partial illumination from a nearby 400wt 20,000k Radium (also on PFO HQI ballast). A 400wt halide should be more than enough on a 22" tall aquarium.
Can i get any clam in my 55 with 260 watts of VHO?
I would advise against it. It would be much better off under more intensity. However, you could most likely keep an H. hippopus successfully under that lighting. However, they're not the most colorfull clams
Graham