pfo 400 watt ballast and 20k radiums

[chwkreefer]

I know there probably has been a lot of past discussion on this topic. But if some of you wouldn't mind, could you tell me what is the most recommended ballast for the radiums?

So far based on what has been said, if I am correct, the radiums will work with the regular PFO ballast but the intensity is somewhat compromised and so the bulb will not appear as bright and but will appear more blue than with the ballast of choice. Correct? (boy that was a long sentence, I'll have to catch my breath)

Bill