here is my problem

[Delphinus]

Maybe I'm off-base here (Mike correct me if I'm wrong) but I think what he's asking is, he has a 400W MH ballast and a number of different bulbs he could run off that ballast; and should he keep that or should he trade it for a Icecap 660 with 4 VHO tubes.

If I understand your tank size correctly Mike, I think the Icecap will not do it for you, but I think it would be fabulous supplemental lighting. But 30" deep, if it was me, I'd be thinking of hanging onto those 400's. That's just me though, I'm quite partial to halide lighting. Only thing is, I'm not sure if you have a dual ballast or two ballasts: one 400W bulb over that tank is going to look kinda silly (very bright in one spot and very dim at the edges). Two bulbs over a would be OK, three would be even better. But that's definitely a lot of juice, if that's a concern then maybe you DO want to start with the Icecap and work out from there over time.