Sounds like they are electronic ballasts. Electronic ballasts are suppose to fire all bulbs. I believe HQI bulbs are over driven by the ballast by design. I once tried a regular DE bulb on a HQI ballast and it ended when the bulb exploded after about 15 minutes. :)

That is where I still get confused. Some articles state that all 250 DE bulbs are HQI and run best on magnetic ballasts. One article said Radiums should only be run on magnetics.
Maybe because they "overclock" the bulbs...

Here is possibly the most definitive guide to mh lighting for reef tanks.

http://www.manhattanreefs.com/lighting

Magnetic ballasts, transformer & capacitor may be old school, but in my experience they are robust. Years ago when I was running two 250 watt MH mogul base lamps, I was itching to switch to electronic ballasts. I waited, did some reading, watched forums for threads on electronic ballasts. There was a lot of traffic regarding failure of electronic ballasts & the inability to repair them cost effectively. In the end, I'm glad I never pulled the trigger.

Magnetic ballasts are simple and most are repairable. Generally what fails is the capacitor or the igniter if the ballast has an igniter circuit. I still have my 250 watt magnetic M58 Advance ballasts in the basement gathering dust. Both are serviceable, but I've switched to LEDs. I think I changed a capacitor on one of the ballasts to keep it going. A few dollars to replace. Most electronic MH ballasts are non repairable, being completely encased internally with potting compound. Once they fail, they are trash, much like fluorescent light ballasts. So for a minor gain in efficiency & the reported ability to fire many different MH lamp types, you are sacrificing the ability to repair them once they die. A little research on which magnetic ballast fires your lamp, whether mogul, double ended, hqi etc. will probably serve you better in the long run than switching to an electronic version.

If you care to do some further reading on the subject of high discharge ballasts, here you go.

http://code-elec.com/content/00/01/5...ting-guide.pdf

http://media.hydroponics.net/product...cket_Guide.pdf

Either way, IMO folks with MH & fluorescent fixtures are going to find it increasingly difficult to source parts for their fixtures. And those parts will rise in cost as manufacturers shut down production due to lack of demand. Like it or not LEDs are eventually going to take over, for almost any application except for specialties such as heat lamps.