VHO ballast

[fishman1218]

I have a 150 that I am looking to add some vho supplements to, right now I only have halides over it and would like some blue. I've been looking around and can only 2 companies that make ballasts to run 72" vho's(ice cap, the 660 and aro, the 4lx model) . Are there any other ballasts out there that will fire 72" vho's and are there any that will fire more than 2 bulbs ?

Thanks