lumatek ballast question

[420forme]

I have a 400 Watt lumatek ballast (the purple one) and it has settings for 250,275,400,400sl. So can I run a 400 Watt Hps at 250 or do you run the proper wattage bulb for each setting? I ask because I currently have 400watt bulbs and its getting to hot so I thought mabye I can run it at only 250? Anyone know?

 

[FuZZyBUDz]

u just use the 400 watt bulb, but with regular HPS or MH bulbs on these dimmable ballist, turning that knob is killin the hours of your bulb. a digital bulb would be a great help if u want to dimm it with out ruining ur bulbs lifetime down to half.

 

[EvlMunkee]

u just use the 400 watt bulb, but with regular HPS or MH bulbs on these dimmable ballist, turning that knob is killin the hours of your bulb. a digital bulb would be a great help if u want to dimm it with out ruining ur bulbs lifetime down to half.

Excuse my ignorance but ...a "digital" bulb?
I have the same situation. I don't know what a digital bulb is. I use an Ushio 400w enhanced OptiRed bulb. I don't know if it is digital or not.
Could you explain to me please?