i had 2 croceas under pc's and the looked great and were spilling over the shell and then they just died one day. Water quality was fine. I don' think PC's can sustain clams long term. I had mine like 3 months.
This in in response to PEMfish. I've had him for six months under pc lighting and hes grown about 1.5 inches. Clams can do fine under pc's if they are under high quality lights that are replaced evry 6-8 months. Feed plenty of oyster eggs and phyto and excellent water quality doesn't hurt either. Just my 2 cents.
I think that is why they made us mods Frankie. I have 4 and a lookdown box.
Can't wait to see the great pics in this contest. Clams are one of my favorites.