what makes no sense to me is regardless 8 on 16 off it's the same as 4 on 8 off x2 in a 24 hr cycle......
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I always figured that the corals had eons to adapt to roughly 12-hour cycles and that it wouldn't be beneficial to change it from that. However, I definitely don't have any data to back that opinion up.
CJ
Not that our aquariums mimics nature to a T or anything, but I (And completely a guess) don't think this holds water. I mean I've had a marine biology friend, years ago, tell me that he leaves his frag tank lights on 24/7. I wasn't going to argue with he guy, but sometimes I wonder where these ideas come from. :xd:
I hope it does work, no one will ever shy away from more growth!
I always figured that the corals had eons to adapt to roughly 12-hour cycles and that it wouldn't be beneficial to change it from that. However, I definitely don't have any data to back that opinion up.
CJ
what makes no sense to me is regardless 8 on 16 off it's the same as 4 on 8 off x2 in a 24 hr cycle......
Could be the first r2r controlled experiment .
If the corals were "tricked" by the day night acceleration I wonder if you could feed 2x as much too? If so that would have to affect growth.
Lol- sure, if people want to hook me up with the supplies, I'll gladly run the experiment. would plumb 2 20 gallon tanks into my new frag system, each on it's own "shelf" that would be closed in on most sides (so ambient light wasn't a large factor.) and hook up identical lights to both. One would run 4 on, 8 off (so an 8 hour photoperiod) the other would run 8 on, 16 off. I would just need the lights/bulbs and a decent pump to pump to both of them, and then could take some existing colonies, chop in half, and place in both. Could do some SPS, some Acans, a head of hammer in each, and of course, a variety of zoas, PE's, and paly's.
Sounds like a cool idea. However, without running many such experiments, unfortunately you are not really proving anything.
CJ
agreed- but if I got disparate growth rates the first time, it would at least make the hypothesis more plausable and give others encouragement to try it as well, right? Or perhaps after doing it for a time period, swap the schedule on the control and the experiment tank, and see if the growth rates then balance again. While not provable to a 'law', it would go a long way towards establishing the hypothesis. A lot of accepted research is based on much flimsier experiments (Stanford prison to think of one)
disclaimer... I'm no marine biologist...
Here is the paper that the 4 on 8 off cycle was derived from.
http://people.oregonstate.edu/~weisv/pdfs/Yacobovitch%20et%20al.%2004.pdf
If you look at the graph on the page labeled 38. You will see that peak motility of the zoox being studied occurs at about 3 hours of light exposure and then begins to fall off steeply after 4 hours.
"3. Results
3.1. Rhythmicity of algal motility
Motility of freshly isolated algae from mature colonies of H. fuscescens exhibited dielrhythmicity under a 12L:12D cycle over a 5-week period (Fig. 2). Algal motility began
0–1.2 h after the light was turned on, and became most intense 1.5–2.25 h after that time (lag time) with a peak duration of 2.5–4 h (Table 1). Peak motility period lasted 1.5–2 h.
Motility then gradually decreased and ended 3–5 h before dark. Motility duration was 7–9 h and was never observed during darkness."
Also note about constant light exposure...
"No motility occurred when algal cells were kept under continuous dark. Furthermore, no
motility occurred when algal cells were kept under continuous illumination immediately
after isolation or after initial 12L:12D cycle for 3 days and then transferred to constant light..."
While this article focuses on motility of zoox I believe the thought process is that energy levels peak around the same time period motility peaks and hence is able to maximize energy to the coral tissues.
I reset the lights on my frag tank to 6 on, 6 off.
It will be interesting to see if it makes a difference in growth.