What is the 5th known species of Tridacna clam?

[MartinM]

I’ll jump in and say the Red Sea LED’s do not grow clams well IME, they’re too blue, and clams tend to have a lot of blue pigmentation, reflecting blue light. Anecdotal yes, but I have a dozen clams under various lighting, and switching from the Red Sea LED (which is mainly just blues, ugh) led to a lot faster growth without a significant increase in PAR.

Maximas get large, btw, but Croceas don’t. Both need 350+ PAR!