"Broken" MH Light Fixture - Help please

[ShirleyM]

Hello,
(120-gal reef)
Our MH lights are not working... first one was cracked - that's never happend in 7-1/2 yrs to have one crack. We replaced it. The new one cracked apart the same day! We ran the reef with only one Halide bulb for awhile... moving the light-needy corals to that side of the tank. Two nights ago the ballasts or something made a loud whining noise and it got louder and louder... we turned the light off.
Below is our lighting specs... what do we need to buy?

* two 175w 10,000K metal halide bulbs, 4" fan.

* Custom Sea Life ballast - one switch for each bulb. 120V 1.80 Amps/Lamp
216 Watts/Lamp

What do we need to do to fix this? The corals currently have a 36" PC strip over them, and they are beginning to look sad...

THANKS!
Shirley

[VWD]

I really don'r know, But 7 1/2 years on a ballast may be the life of the ballast and it is going out, Breaking the bulb is stange. I think You may have to replace your ballast. Maybe someone else will chime in with better info.