[jtravapd]

i have a coral life aqualight 72inch metal halide fixture since august...i have noticed over the past week that the metal halide all hte way to the right doesn't come on with the other bulbs....the other bulbs come on, and that bulb just makes a long buzzing sound, then after awhile the buzzing stops and the bulb comes on....is this normal?...i am afraid it could be a fire hazard.....

[NATIVEVAMAN]

Generally when mh bulbs go bad they flicker for a while before starting.When its a ballast you get loud buzzing and slow starts.

[jtravapd]

well, the ballast is located underneath my tank and that doesn't make any sound...the buzzing is actually coming from the bulb...or the bulb area.....then it just goes away and the bulb lights..

[sgarron]

Try swapping the left bulb and the right bulb. That will tell you if it's the bulb or ballast.

[reefcouple]

Steve hit the nail on the head... I just did the exact same thing.

[pogodzib]

Also, when MH bulbs fire up, they use up more power than when they are running, so the current draw on your electrical line may be causing the problem. The clocking noise you heard is from the bulb trying to ignite, which is why it stops once the bulb is fired. The issue isn't going to cause a fire. If your ballast gets bad, it won't be able to keep the bulb lit or the bulb may appear a different color (usually more yellow), but that should be the only issues. If the bulb is bad, it won't light or will be a different color. Also, if a bulb is hot, it needs to cool down before it will re-fire.