i just started up a new tank and i mainly want to keep clams and some sps or lps corals. the tank is a 65 gal 36x18x24 with overflow and 20 long beneath it. 3.5" DSB and Kent Nautalis (sp?) skimmer. the lighting is; 400 watt German 10k halide in a hamilton reefsun fixture, 4 55 watt powercompacts 2 6500k and 2 actinics. is this sufficient lighting to have any clam that i want in the tank? i want mostly maximas and croceas, with a few derasas and squamosas. i read Knopps book and i thought that this would be sufficient lighting for such a tank but cruising this board i see a lot of different halide choices. mostly being the radium 20k 400 watt bulbs. would the 20k do anything better for the tank or is it mostly for the enjoyment of the aquarist? thanks for the help everyone.