bulb replacement help


New member
I bought a full aquarium setup from a fellow reefer. It came with a 150W Metal Halide with a double ended 10,000k bulb.

If I don't know how old the bulb is, how do I know when to replace it?

When I do replace it, which probably needs to be soon, what is the best place to buy a new one?

Thanks for your help.

Tom Fay

New member
If all you have is fish, replace the bulb when it burns out. If you have corals assume it's time and replace it now. Metal Halides, like all bulb types, slowly decay. Your naked eye can't see the shift in color or intensity so you just have to get on a schedule. Usually 12-18 months on MH.


Acropora Nut
I'm pretty sure you want to replace MH's every 8-12 months since they lose up to 70% of their intensity after a year of use.