how long do VHO bulbs last?

[reefNewbie]

I was wondering how often to change the URI vho bulbs?

 

[Kenzy]

Depends on who you ask...anywhere from 8-18 months. I change mine out once a year and write down the date that they were changed on so I don't forget. Some people also like to change out half, then do the other half in 6 months time so that they are not going from old lamps to new lamps in one go.

 

[Len]

I own a PAR meter and I've concluded that after about 8 months old, VHOs have diminishing returns. So I aim for about 8-10 months replacement.