A few questions/responses to what has been posted thus far...
Yes, I am on a budget... though I also know the value of doing it right the first time. I'm pricing out a few options, this is only one of them.
I find it hard to believe (thinking logically about it) that two 70w bulbs will generate basically the same amount of heat as two 150s or two 175s. Is that really the case?
A few of you I'm unclear on your recommendation - are you saying I should go with one bigger bulb (either a 150 or a 175) or two?
So here's why I'm thinking what I'm thinking... those of you who think I'm making a bad decision, I'd love some counter points (not because I don't trust the board, just for my own education).
First off, the tank is a30long (36x12x17).
I want 2 MH bulbs because...
I've always heard that the effective light from a MH is only about 1' to 1.5' square. That's not to say that it won't light up the entire tank, but you only get MH quality light in that area. Also, I don't want to be governed where I put corals based on light (i.e. sps only in the middle directly under the MH, etc.).
I was thinking 70w bulbs because...
The tank is not very deep. I have a 70w halide over my 12g Aquapod and it does wonderfully. It is ~16" deep, so light penetration from a 70w bulb over the 30g should be the same as over my Aquapod. A 70w bulb, from my experience, is enough to keep SPS and clams. Two 70w bulbs will give a nice even light over the entire tank - any coral can be placed almost anywhere in the tank.
I was thinking two actinic T5s because...
Mostly for coloring. I want to go with 10k MH bulbs because they seem to promote better growth. I could probably do actinic VHOs as well, but T5s seem to be more efficient, so...
And BTW... thanks for all the advice. This has gone from what I thought to be a pretty straight forward question to a good conversation. This sort of thing reminds me that I don't know as much as I sometimes think I do.