PCs are great for lower light corals, as Ray said. Deresa clams could handle PC
lighting, as they are a lower light clam. I had the 2x65 PC
on my 29 gallon for 4 years and I grew corals very well. But I agree, you'd definitley want to upgrade for clams and sps
FWIW, I have the 4x39 Current Nova Extreme HO
-T5 on my 24 inch deep 45 gallon tank, and I love it. I don't have clams yet, but it's in the plans for the future, and my sps
are just eating up the light. It runs very cool, doesn't use as much electricity, and is relatively quiet. I think you'll be happy with thr 4 x 54 watt fixture. Just as with any tank, keep sps
towards the top and lower light corals in the bottom.
I would have loved to do MH
, but cost prohibited me as well, and I also didn't have a place to hang it. T5 is perfect because they are cheap and aren't mega powerful, so can sit right on the tank top (with the legs of course).