400w MH vs 600w MH

Alright, I'm gonna give a little background before my question. I just bought a lumatek 600w Ballast, a sunleaves air cooled reflector, and a 6" can fan all for $200 from someone on Craigslist. (Pretty good deal) The guy threw in a 600w HPS bulb and a 400w MH bulb.

My question is: Should I invest in a 600w MH bulb or should I just use the 400w he gave me? I'm gonna be running 4 autos. I'm gonna have 4 t12 bulbs for side lighting and 8 23w CFLs hanging (2 in each corner) for a little extra lighting. Would going from 400w to 600w make that huge of a difference?

It would be cheaper to get a 600 bulb. You would need another ballast for the 400. Some dimmable ballasts can supposedly run lower watt bulbs. I wouldn't chance it. I've seen one time a lower bulb wouldn't fire up. Then wouldn't work at all. But that could have been an isolated incident.

good luck and happy growing.

i've ran a 400mh on my hps ballast, it just runs hotter. a lot hotter i might add, i don't know much about the safety aspects but i had no problems using it for over a year.

ghb were you running it on 100% or did you lower the power when it was running super hot?

you got a 600w ballast, run a 600w bulb not a 400w.

Alright. I'll go with a 600w MH then and toss the 400w. Is the side lighting pointless? Or would it at least have a little effect?