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View Full Version : How many VHO bulbs on one ballast?


moze229
09/30/2007, 06:23 PM
I'm setting up a FOWLR 56 column soon, and I think I want to go exclusively with VHO. I like the VHO lighting and I don't want to have another MH setup burning 8 hours a day. I know I could go with NO, but I just like VHO so leave me alone :)

Anyway, I've never seen a VHO setup with more than 4 bulbs running on one ballast. Even vendors such as Hellolights sells max 4 bulbs per ballast. Is there a reason for this, or does it depend entirely upon the wattage of ballast? In other words, if I were to use a 500W ballast, can I run 6 bulbs instead of just 4 (75 watts each on the bulbs)? I suppose I could just run multiple ballasts, but one would be better :)

I'm going to be limited to 24" bulbs on this setup, because the tank is only 30" long. To my knowledge, VHOs jump from 24" up to 36". I have plenty of room depth-wise to run more than 4 bulbs. Maybe I should go with something else?

Matt