How long to leave on the lights?

[Riclat]

My 120g reef tank is lit by 2 250 MHs and 2 vho actinics.

I have a variety of softies as well as some small hard corals and fish. I currently leave the actinics on about 7 hours a day and the MHs about 4 hours. Is this enough to get good coral growth?

 

[SeanT]

Is that a total of 7 hours of light?
If so, I would say thats a few hours too little.

 

[waynem]

So 11 in total? I would run the MH longer. but keep the same total

 

[Riclat]

11 total hours, but both types of lights are on at the same time for 4 hours. I'd like to leave the MHs on long but to do so might require getting a chiller.

 

[mcrist]

I switched to 5 hours of metal halide a day and my corals seem fine. Only time will tell.

 

[Entropy]

To me the most important aspect (call me selfish) is that the halide(s) is/are on when I am home and most likely to view the tank. My lights come on at 3pm because that is when my wife and daughter get home. The halide goes off at 8:00pm which gives me about three hours to veiw the tank under full lighting. The actinics (T5's) go off at 10:00pm which is usually when I am getting into bed.

 

[AugustWest]

I'm down to 5 hours a day for my MH's. I used to run them 10 hours....Corals look great.

 

[schaef]

I have a 120 with 2x250W HQIs. I leave the Halides on for 8 hours each 12-8pm and 1-9pm.

 

[Riclat]

Shaef,
What kind of chiller do you use?

 

[amore169]

I run my metal halides lights from 1pm to 9pm and the actinics from 12pm to 10pm.