MH bulbs how long do they last

[newreef06]

I have a question about MH bulbs. How long do the bulbs last. I keep my lights on 8 hrs a day. Also I had my bulbs since nov 08. So about a 1yr and 3 months. I notice I have gotten alot of brown algea over the last few months. Do they need to be changed???

[golfish]

depends on the bulb and ballast...I'd say 15 months is too long for any MH.

[Sk8r]

I let mine go 6-8 months.

[newreef06]

I just ordered new ones today. I should have them next week. Im getting ready to upgrade to a 90g. So it will be good to start with new bulbs

[Spssteven]

I only use my bulbs for 6 to 9 months at the longest

[Shane Hoffman]

I go 12 months on 250s. If I had 400s I would probably change them after 8 months.

[Doc's_reef09]

i had mine for about 8 months at a time.

[luther1200]

I go 10-12 months.

[richpoolboy]

depends on the bulb and ballast...i'd say 15 months is too long for any mh.

+1

[BigMike75]

How long is everyong running there MH's? My VHO's are my main lights and my MH's are just going to be run 4-6 hours a day.

[pco1988]

I change my 400w Monguls out every 6 months

[dots]

http://reefkeeping.com/issues/2007-04/ac/index.php

This is relevant to your question.