The room housing my display tank gets a fair amount of light through the the shaded windows from 7:30 am to 8:00 pm. Not enough to read a book or anything, just not pitch black. Currently the MH over the display tank is on from 4pm to 2:30 am. the PCs over the refugium are on from 6:30 am to 4:30 pm. When they are on it casts enough light on the display tank to look like a full moonlit night in there. This means that the tank is only in complete darkness from 2:30 am to 6:30 am. See my post on the tank specs forum for details on tank and livestock.
I would like some input as to whether the above is a good scenario, considering the following:
Joyce D. Wilkerson reports in her book "Clownfishes, a Guide to Captive Care, Breeding and Natural History," the results of an internet survey of tank owners who successfuly kept clownfish hosting anemonies alive puts their photoperiods between 12 and 13 hours per day
I would soon like to introduce 3-4
giant clams to this tank and Daniel Knopp advises in his book "Giant Clams; A comprehensive Guide to the Identification and Care of Tridacnid clams" to use about an 8 hour photoperiod when using metal halide bulbs, but that it is okay to have a simulated dawn and dusk lighting with flourescent tubes.
What would be an advised compromise between these periods considering the light parameters mentioned earlier? Would it be advisable to add flourescent tubes to this setup even though the diplay tank receives some light from other sources already?
Also, Daniel Knopp reccomends that "at least ten hours of total darkness should be allowed" for the algae to transform carbondioxide to glucose. From anyone's experience with their lighting setups, does the light entering the room from windows pose a problem here?
Sorry for the long post. I've just been accumulating questions without answers.
