Lighting Question
 

I have a std 72 gal tank(4ft) 18in deep setup for SPS.( I currently run 2 175 watt MH and 2 40 watt 03 Actinics)

If I have 3 choices to light this tank...T5, VHO, MH

My question is how many bulbs do I need to run SPS?

My setup would be 2x 250 w MH and 4 T5s

You would need 6 or more bulbs if you are planning on running t5's. which t5 fixtures are you looking at? also have you considered combo units, best of both worlds

Agreed, the combo unit lets you have that T5 "pop" with the Halide "Shimmer". Mind though, I have a 8 bulb tek 5 on one tank and a 400w Halide with suplement T5's on the other and I love both of them.
Levi

i would have to agree, if you can go with a combo unit do it. You can get good par while still getting the color you want.

The reason why I ask is that i just blew out my MH and had to use some VHOs as temps. These are a mix of 2x12k and 2xactininc (URI's). Turns out I actually like this combination. They bring the more subtle colors out in the SPS. The MH are at 14k(reef optics) with supplemental Actiincs. I notice that tank is lit "more" on 4 VHO's(T12) as opposed to the system I have now. Maybe I should add more actinincs and ease up on the 15k MH's to 12K MH's