when to change out bulbs

[Medman]

I've been running my 2 72" VHO's and 3 250watt 10K MH's for about a year now. When is the right time to change them out?

[sher]

i think its time.

[icemark]

What ballasts are you using?

For the VHO:
An Icecap, maybe 12-18 months is normal bulb life, but for a Tar ballast maybe 6 to 8 months.

Most other brand electronic ballasts run around 10 to 12 months.

For the MH 12 to 18 months again is pretty normal for the 250watt bulbs at 10 hours a day (with the exception of the 250 Iwasaki which can live with decent light up to 24 months).

[Medman]

I have icecap ballasts. But my MH ballasts I bought were to run 6500K 250watt iwasaki's. I had the iwasaki's for awhile, but I thought it was a little yellow for my liking. Then switch to 10K's. I might switch back to the iwasaki's. That's why I was thinking about changing.

[PRO-AQUARIA]

ON your 6 footer`s try one at a time over a 10 month period. one tube at a time ever week. i mark my bulb`s with a marker with the date on it hope this help`s