The difference we see in the fluorescent radio frequency ballasts, is that they product more of a High Pressure Mercury discharge spectrum in addition to the usual Low Pressure Mercury discharge spectrum. This is especially true for DC output ballasts such as IS (Insta-Start) ballast, as compared to the usual cheapper RS (Rapid Start) magnetic ballasts.

I'm using IS ballasts on all my fluorescents (T12, T10, T8 and T5HO ), but I also use outter Red Safety filters to eliminate stray 520nm and lower wavelengths (they don't cut out much more than the original Yellow Safety filters we hoped would work and are espectially good when combined with Red and/or Far Red phosphors to begin with).

Take care, Sal.
salmayo Reviewed by salmayo on . HID Time factor manipulation I've been following the UV-B thread for a while. Cool stuff. Makes me want to get back into growing. But, what really gets me going is the Martian stuff and the light time factors for increasing tric production. I seems to me that, unless you've got a ton of cash for LED's or have alot invested in HPS setups already, it's really hard to get down to the magic 1.8 and decent yield. However, I have some ideas to get closer: Fluorescent Supplemental Lighting: http://kinoflow.com has HO Rating: 5