Cool thanks Gordo.

The ballasts I have, and ran them on were from Upper Valley hydroponics, etc. I may have got one from Buchannan.

I just went and dug up the last iwasaki I've had, and the old ballast I used to run it on (pack rat). This bulb is maybe 5-6 years old. I was hoping your bulb part number would have been different indicating things have changed.. doesn't seem that they have.

My old bulb is an MT400DL/BH *- E39/41 as well, and it says "clean ace" on the glass sleeve. But, there's no "R" at the end of the numbers as you indicated. There is an "R" on the glass sleeve though.

The ballast I used to run this on was an Advance 400w for M59 or H33 lamp..

M59 being the Metal Halide, and the H33 the Mecury from what I recall.

The new ballasts I'm driving the 5500k ventures with are actually Venture Lighting ones - rated for M59 & H33 400w also. Just checked that now. They are both Upper Valley Hydroponic specials.

I've never got a fancy ballast for bulbs (PFOs, blueline, etc.). I wonder how much of a diff that would make. Mind you, I've never run HQI bulbs either.

I've wired all my stuff, so that's not a problem.

I'm wondering whether to get a hold of the new iwasakis, run two of those, with one Radium (in the center) to get a nice coloration along with the actinics.

Any of you know whether the Radiums can be run on joe shmoe ballasts? Or do I need a fancy dancy one?  ;D