20K Radium bulbs and ballasts

[Chris Lakies]

Since ordering my dual 400 watt PFO regular ballast, I've been reading that in order to fire the German made bulbs you need a "pulse start", "electronic", or "HQI" ballast because the German bulbs are made to fire off of 220v as opposed to a American 120v, is this true???

[kevinpo]

My Radium fired just fine on my 400W PFO regular ballast. I ran it on 2 different tanks with 2 different ballasts and it always fired. It ran a bit more blue and dim on the PFO regualr ballast compared to the PFO HQI ballast (I have both).

HTH,
Kevin

[Ninong]

Sanjay Joshi tested the 400w 20,000K Radium bulb on both the regular ballast and the HQI ballast: http://www.personal.psu.edu/faculty/...omparison.html

As you can see from his test results, the 400w 20,000K Radium bulb puts out 21.6% more PAR on the HQI ballast than on the regular ballast.