New Radiums wont light without a tap, help.

[Live Water Aquariums]

Ok, I have a really old hamilton 2x 250 watt magnetic balast running 2 se mh bulbs. Before I ran ushio 10k, xm 20k, coralvue 14k, 20k, reeflux 12k, all have always light up right when the timer kicks them on no problem. One light burnt out a few weeks ago so I replaced them both with new 20k radiums. First of all these are by far the best look I have ever seen from a mh bulb. Super bright with unreal crisp color with just the right amount of blue. However, they never seem to light up on there own. I had the reseptionist tap the bulb lightly with her pen and they lit right up. A little friction, tapity tap and they light. So what's the deal?

My first instinct is to replace the mogul, they could use a better reflector anyway, but it seems more like it's the ballast. I didn't have any problems like this with any other bulbs, is there something with the radiums they need a stronger pulse to start? Do I have to get them a new ballast or what. Any Ideas? please help.
Thanks, Kevin.

[KT-150]

radiums require either a pulse start or HQI ballast. you may need to replace your old one if you decide to keep the radiums. great bulbs. btw.

[Live Water Aquariums]

Such a simple solution. I was afraid that was the answer. I kind of remember reading that somewhere. Some of the other bulbs I used were hqi bulbs incased in a single end bulb and they worked fine, why not my radiums?

[KT-150]

Such a simple solution. I was afraid that was the answer. I kind of remember reading that somewhere. Some of the other bulbs I used were hqi bulbs incased in a single end bulb and they worked fine, why not my radiums?

hqi in a SE? Dont know much about that. I have 2 X 250 PFO pulse start ballast Im not using since I switched to 400w. PM me if interested.

-Kris

[DaveMorris]

It is definately the ballast. I had the same thing going on until I figured it out. You need to run bulbs that are rated for an M59 ballast. I use aa dual PFO 400w and a dual PFO 250w for my tank and I love it. I am using Hamilton 14,000k lamps and they look great.

[Live Water Aquariums]

Thanks dave, I actually replaced them with Hamilton 14k bulbs. I didn't like the hamelton de bulbs but I was pleasantly suprised by the hammy 14k se bulbs. Lit right up and looked oh so good. Much better than replacing the balast. Now I'm thinking about a pulse start balast to go with these extra radiums for the garage?