250 MH enough for 30 inch deep tank??

[Willito]

It's all about the type ballasts and the reflectors folks. BTW my clams are doing fine on my sandbed, which is about 30" from the surface.(250W DE). I also have another clam sitting half way up the tank that is doing just as good as the one below. Both are maxima's and maintain very similar color intensity and growth rate.