I had a crocea in the mid rock level in my 65 before I upgraded. I ran 1-250 watt MH and 2 T5 actinics in that tank. Clam did very well and now is in my 90.
I waited almost a yr with my tank before adding the first clam. I now have 3 kinds in 2 tanks with a Crocea, Deresa and Maxima in the mix
I grew clams just fine under 2 x 150W HQI's; however, coloration is much better and growth much more rapid under 250W halides. You should be fine with your current setup given the tank depth and clam placement.
<a href=showthread.php?s=&postid=11692912#post11692912 target=_blank>Originally posted</a> by cj hill i have a maxima in my 65 with one 250hqi and 2 t5hos it has been in there for 2 years and is doing fine on the sand with a flat rock under it