Length MH Lights Should Be On???

[hurrifan]

How long should my MH be on? I currently have them on for about 10 hours, is this too long? And, if they should not be on for this long, what should I do to provide "white" light for my tank? Should I add another PC ballast and add 2 96W PC lights? That seems couter-intuitive... Please help.

 

[2poor2reef]

What's the duration of daylight at the equator. Think about it. What fraction of natural daylight are you providing with your mh lights? What depth are the plants and animals in your tank accustomed to living, as that will affect how much of that natural light would reach them. I think that people run shorter than natural photoperiods to reduce algae growth or other problems that are best attacked at their source such as by reducing available nutrients rather than by restricting photoperiod. We used to do the same thing for the same reasons when we ran our reef tanks at temps in the mid-70's. Many of us now run our tanks in the low 80's and deal with the higher metabolic rates by managing the system's import/export better. My opinion only.

 

[davelin315]

Approximately 10-12 hours.

 

[djh]

I have PCs come on from 8 to 8, my MH on from 10:30 to 5:30 and my actinics 7:30 to 8:30.

 

[aliaird]

I have my actinics on for 14 hours, overlapping my mh's by an hour each end (ie the mh's are on for 10 hours - 8.30am til 8.30pm)

I might try to adjust things so that it goes darker earlier so that when i go to bed at approx 11pm the tank has been fully dark for a couple of hours so i can see the nightlife coming out under my "moonlight" flourescent. I haven't the energy to stay up late to have a good look at what goes on in the tank in the middle of the night!