Mh Bulb Replacement?

[Bill Shea]

how often should mh bulbs be changed out?

 

[mfinn]

I change mine out every 10-11 months.

 

[mflamb]

That's going to depend on the bulb and photoperiod.

I've been changing my Aquaconnect 14K bulbs that run 6 hours per day every 12 months.
Now I have a PAR meter and I'll change the bulbs when they get down to 85% of the 1 month PAR measurements.

 

[grigsy]

I generally change mine out about once every year.