4 on 8 off light cycle

[Troylee]

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...... :confused:

 

[Electrobes]

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

That's what I basically meant to say. :D

 

[Wy Renegade]

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

I basically used to think the same as both of you, obviously light in the ocean doesn't go on and off in a 4 hour cycle does it ;)? Then somebody pointed out something I hadn't even considered; high and low tides. Since water depth changes over some reef areas based on high and low tides, lighting also varies with periods of very intense lighting, and periods of almost no lighting. So I figured what the heck, I'll give it a try.

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...... :confused:

Agreed Lee, and as I stated, I don't know that it truly makes any difference in growth rate or not. What I really do like, is that I get to see my tank with the lights fully on both early in the morning before leaving for work, and when I get home in the evening after work, without having to run a super long light cycle. I don't see any serious disadvantages to the idea, so for my I'm trying it to see. With this system, I'm also able to run the sump light on an opposite cycle with the tank for six hours during the day, without disturbing my rest LOL.

 

[steveb]

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.

 

[Tabasco1]

I will look for the link tomorrow, but I think I have read that speeding up the light cycle by 2x will also induce some fish to spawn quicker as well. For instance if they are spawning 1x per month they will start spawning 2x per month. Let me check that out though. Don't want to spread lies.

Also, this sounds like it could be a great experiment!

 

[drainbamage]

I'd love to try a controlled experiment, would just need the space to do it in, and well, the equipment, lol.

It does make sense if you think of it in a biological sense, not a math sense. We add the numbers and figure it's the same- but the corals don't do math- they sense more the homer simpson way "light on, light off, light on, light off" so hence the 'tricking.'

that's the way I'd see it in terms of a simple rationalization of how this method could/would/does work.

 

[Tabasco1]

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.

 

[drainbamage]

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.

 

[CJO]

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

 

[steveb]

http://people.oregonstate.edu/~weisv/pdfs/Yacobovitch%20et%20al.%2004.pdf

 

[Kbra]

Here's the paper...

http://people.oregonstate.edu/~weisv/pdfs/Yacobovitch et al. 04.pdf

Sent from my Xoom using Tapatalk

 

[drainbamage]

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)

 

[CJO]

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)

Of course! I didn't mean for anyone to think that I thought it was a bad idea. The more data, the better and you have done a good job of taking out other variables.

CJ

 

[steveb]

Practical Coral Farming by Miguel Tolosa pg. 109 <-- book where I read the initial info

 

[steveb]

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.

Practical Coral Farming by Miguel Tolosa pg. 109 <-- book where I read the initial info

 

[Troylee]

there i merged the threads and cleaned it up for ya... now there is only one...;)

 

[Tabasco1]

If you actually had 5 people bite and run the experiment, you could look at their data and it would be enough to determine if there are at least tendancies or additional things to consider. I know not a huge experiment with 1000 tests, but even with 5 if all the results were similar, I'd say that is some fairly strong suggestion that there is something to the theory. If they are all over the place, probably there is too much different between the testers to get a good feel and nothing was learned and if all the results showed no improvement or decreased growth that would also be valuable.

 

[Harry_Y]

I have read of this in the past, but what I read was 6 on 6 off.

Since I have a separate frag system in my basement near
my sump, I may reprogram the lights and give this a try.

 

[Harry_Y]

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.

 

[drainbamage]

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.

awesome- keep us updated please!!! A local guy is doing this too, and I'm really tempted to see if I could get the experiment running somehow with a control group-obviously for us farming addicts it would be very worthwhile to prove or disprove the study.