amount of light periods

[Mr. S]

Kind of a survery question.
How long do you run your MH lites?
How long do you run you actinics?
Read lots of stuff on it and as usual I am finding out from you locals what your time frame is. Right now I am leaning towards 6 hours MH and an hour and one half of actinics before and after the MH cycle. Any thoughts. Would like to do minimum lights with maximum growth!!! (don't we all)

[Ryan Mackey]

We run actinics from 9a-9p, outside 250mh's from 11a-8p, and center 400mh from 1130a-700p(on the show tank) and have never changed this timing to test if there might be a more favorable photo-period. The new tanks have 13000K bulbs in one and 10000K in the other, which may indicate a different light cycle length. 20000K bulbs are strong in actinic but have sharp drop-of of light intensity after about 470nm. 13000K bulbs have a curve similiar to 20000K but plateau higher through the visible spectrum. The 10000K bulbs are reported to have the most natural allocation of light across the spectrum, are much lower in actinic radiation, and replicate the light as it would be within the first 5 or 6 feet of water column over the reef.
Do you need less MH hours at 10000K than at higher color temps? Does everyone stagger thier vho and MH? Is there one correct answer? I think the answer is no.
Probably most people set the light hours initially and then modify them based on what thier animals are "telling them" or based on the amount of heat they produce.

[Krux]

my halides run for 6 hours, and the actinics for 10, 2 hours each way of the halides.

was planning on adding either 2 more vho bulbs, or 2 t5 bulbs to give more actinic to the tank, as well as to cool off the colors a bit when the halides are on, doing that i might cut back on the actinic by 30 minutes each way og the halides, at least in the beginning.

i had been contemplating swapping out my 10k bulbs for 13k bulbs when the time came, at which point i would probably step them up another hour to make up for the lower par.

[wanareef]

Our first actinic comes on at 8am and off the same time in the PM. The mH's come on for 8 hours inbetween the actinics.

hth

[Phil_g1017]

First actinic on at 7:30am, 2nd actinic on at 8am (both 6 ft vho) , 2 MH 175w on at 9am off at 9pm. First actinic off at 9:30 2nd actinic off at 10pm

MH are on 12 hours I do this to make up for the fact that the MH are only 175 watts. In addition to that I like to look at my tank so I like keeping the lights on longer than what may seem to be normal. So my fish start going to bed after the MH switches off but while the actinics are still on..

[jfly]

I just have one lamp over my tank and it runs for 12 hrs a day plus or minus one or two pegs in the timer..