Why MH over PC?

[AttackDonut]

I have seen comments about using MH lights for such clams as the Maximas, but have also read you can use PC lights for such clams as Squamosas.

The question I have not seen answered is why MH over PC for Maximas?

I have 130 watts of PC lights over my 5.5 nano and it seems it would be enough, but I wanted to make certain (one way or the other) before I put a clam in the tank that I could not meet the requirements of.

 

[Peabody]

It boils down to that Watts per gallon doesn't mean anything thing

The PAR produced by PCs is totally spread out and does not punch through the water. MH is a point source, has much higher PAR, and then is able to punch it down through the water. Maximas are very light demanding and need TONS of par (in addition to good water quality, etc) I have personally seen maximas under 96 powerquads under 10 gallon slowly die around here. I upgraded to MH so I could keep one myself.

Even if you had MH, I personally wouldn't put one in a tank that small. Stick to stuff more suited for such a cool, small tank

 

[Potsy]

Also, it depends on the clam's habitat. Squamosas can survive under pc lighting because they're probably from slightly deeper depths. Maximas can be found in 3 ft of water that's blasted by tropical sunlight. However, pc are still dim when compared to the amount of sunlight a squamosa would receive in deeper water.