Replacing VHO's

[SomeHairyOldGuy]

I just bought 3 new URI VHO bulbs for my lighting. I put 1 new one in last week and have lowered the light cycle to 9 hrs a day. How long should I wait to replace another bulb? Any suggestions would be greatly appreciated.
Thanks
SHOG

[Firefish]

I never knew this was an issue I do know that if you're going to VHO from NO or to Halide from VHO you have to break into the lighting period but I never did a break in when just replacing an old bulb with a new bulb, I would'nt think this should matter much, no different then when the sun is at a different brightness through out the day. Or even when your bulbs kick on in the morning...I would just change all the bulbs in the middle of the day when the corals have been open for a few hours, the corals will just think there was a cloud passing overhead and now the sun is back out assuming corals think