[organicreefer]

my fish are up with the sun,just like me .problem is their "sun" stays on until eleven .so my fish sleep about 8 hours a night(they are up by 7).is this ok?what about my corals?do they require a longer lights-out(go ahead poke youre eyes out )period?what about "total darkness" as in light from the rest of the room?my tanks are /have done fine on this schedule for a while now...but im interested in others opinions on this matter.

[David]

OR- I got into this hobby because I lived the past twelve years on St. Thomas, US Virgin Islands (latitude 18N). I had a boat, I fished. My wife does not enjoy fishing so I would take her out to a reef, drop the hook and snorkel. It occured to me that it would be great fun to collect some of the fish/critters/corals I was looking at and keep them in my living room. That's how it started. When I got to US a year ago I laughed at what you guys call "live rock", I cried when I had to pay for it.

My answer to your "light cycle" question is this: most of the fish/corals/inverts in your tank come from the tropical regions of the earth (near the equator) where daylight is roughly 12 hrs per day. This does not mean "noonday" sun for 12 hours. Conversely, it is rarely "total darkness" at night, there is ample ambient light from moon and stars in clear sky's of tropics. Most of us want our tanks lighted at night when we are home to enjoy them but most of our homes are filled with ambient daylight in the early morning hours. I run my actinics from 12:30 to 10:30, halides from 1:00 to 10:00. There is ambient daylight in the morning and artificial (streetlight) at night. Considering how foreign the captive environment must be to the inhabitants of my tanks I can't imagine that this derrivation from natural lighting has much effect at all. After all, if you were suddenly locked in a closet for the rest of your life would the "light cycle" really effect your behavior all that much? I have a special interest in a particular fish I used to collect in the Caribbean. Each individual occupied a territory about the size of the average swimming pool. I have three of them in a four foot tank. Light cycle?????????

[organicreefer]

david,
what about photosynthetic corals ,and their evolution with the sun/moon /dark cycles?dont you think that it would definitely affect spawning?couldnt the dark cycle play a role as well,like it does in the flowering/blooming phase of many plants.

[David]

OR- yes, of course, I didn't mean to imply that we shouldn't make every possible effort to "simulate" a natural environment, my attempted point was that we cannot "duplicate" it, especially not when we mix species of various origin at our selective whim. If we really want to pursue the re-creation of an animals natural environment then I think that dedicated species tanks are the way to go, not the "pot luck" reef tanks that are so common. Sorry, I'm getting off point, ... light cycles, yea. What I was trying to say is that reef animals are accustomed to basically constant light ranging from very low levels (starlight) to very high levels (noonday sun on a clear day) with numerous (and irregular) variences caused by weather conditions, moon phases, total eclipses or whatever. Yes the moon phase cycle is probably very important as is a slight seasonal varience. How much this will effect the behavior and activity of a captive reef specimen I don't think we know yet. Probably a lot more important to corals than fish or inverts but who knows? JMO