Photo Period Question

BlackIceClowns · 10/02/2016, 11:25 AM

Hey, I was just wondering... These animals and ecosystem live in the tropics where there is basically 14 hours of light, low intensity, high intensity, low intensity throughout the day... I have that long of a photoperiod, I have my LEDs ramp up slowly which arent that strong (2 Current Orbit Marine Pros) and stay of for a while then 2 of my 4 bulbs of my T5HO turns on for a little (true actinic and purple +) then my blue + and geisemann aquablue coral go on for about 9 hours then the reverse happens and it ramps down to moonlight and actinic on the LEDs, then just the moonlight, then pitch blackness for 2 hours, then moonlight and so on all the way to full day again.... Is it bad to have that long of a photoperiod? I have no observed ill effects, the coloration of my corals and nems is perfect and my purple coralline algae is like exploding everywhere. What do you think? Thanks!

Half Vaped · 10/02/2016, 03:50 PM

Because of my unusual work hours (1 p.m. to 1 a.m.), I keep my actinics on for 15 hours a day: 11 a.m. to 2 a.m. so that I can watch and take care of my tank before and after work. Actually the actinics are shut off for three hours during the afternoon when all the blue-white lights are on, to save electricity, reducing overheating and save bulb life.

My actinics are 2x 80W bulbs and I have two sets of 4x 80W bulbs for my blue-white lights (mixture of ATI Blue Plus, Actinic Plus, Coral Plus and Purple Plus). One set of blue-whites are on for 1 p.m. to 11 p.m. The other set is on for 2:30 p.m. to 12:30 a.m. Each set of blue-whites on the DT have a set of lights on the opposite photo-schedule in the refugium sump.

I have had this photoperiod for about a year and a half and noticed no ill effects on anything. I have clams, acros, SPS, LPS and softies all growing--some fast, others, not so much. Some of my SPS are browned out, which may be attributed to the long photoperiod; I'm not sure.

I think you should be fine. Just be careful when acclimating new corals. I always place new corals on the bottom for a few days to let them get used to the lighting.

BlackIceClowns · 10/02/2016, 06:31 PM

I don't have any SPS and I'm going to leave that until after med school, but I have Hammer Coral, Green Goniopora, Acans, and I have a RBTA and a maxi mini.. they all love the light I give them.. I mean I always could get a metal halide and put it on for 4-6 hours in the middle of the day for the super intense midday "sun", but for now they love it. Just seein what other people think of the long period

Ron Reefman · 10/03/2016, 04:48 AM

You are correct that in the tropics the sun is up for 12 to14 hours However, in the tropics, actually anywhere underwater, the early to mid-morning light and late afternoon to sunset light hits the water at such a steep angle that it's strenght (PAR) is dramatically reduced on all but the radically shallow reefs (1 to 2 feet). That is why most zooxanthellae only do 4 to 6 hours of photosynthesis during the day and then shut down even if they get more high PAR light in our aquariums. For hundreds of thousands of years the have received the same amount of strong sun (9 or 10am to 3 or 4pm) so they have evolved genetically to use that sun. Before and after the PAR just isn't high enough.

Water reduces PAR very quickly. And sunlight coming in at a steep angle has to travel through 2, 3 even 4 times more water before it reaches the corals on the bottom. This reduces the PAR so much that it is unuseable by the zooxanthellae. It may look good to our eyes, but our eyes can dilate and function in dimmer light. Corals don't have that option, their only choice is high PAR levels of 4 to 6 hours of midday sun.

On the other hand, extra long high light photo periods have not been shown to have any negative impact on corals in our tank. They do not get much, if any, benefit, but no negative effects either. The zooxanthellae do require a 4 to 6 hour low light or lights out period. But as long as the light is low enough PAR that the zooxanthellae shuts down it's photosynthetic processes, that's really all that is needed.

BlackIceClowns · 10/08/2016, 03:13 PM

Very helpful, thank you, you've turned me onto another search for papers about this. Thank you.

Ron Reefman · 10/09/2016, 05:10 AM

It's been some time since I read about photoperiods and photosynthesis time frames. If/when you find something, please share it. I'd appreciate a refresher.

10/02/2016, 11:25 AM	#1
BlackIceClowns Registered Member Join Date: Sep 2016 Location: New York Posts: 11	Photo Period Question Hey, I was just wondering... These animals and ecosystem live in the tropics where there is basically 14 hours of light, low intensity, high intensity, low intensity throughout the day... I have that long of a photoperiod, I have my LEDs ramp up slowly which arent that strong (2 Current Orbit Marine Pros) and stay of for a while then 2 of my 4 bulbs of my T5HO turns on for a little (true actinic and purple +) then my blue + and geisemann aquablue coral go on for about 9 hours then the reverse happens and it ramps down to moonlight and actinic on the LEDs, then just the moonlight, then pitch blackness for 2 hours, then moonlight and so on all the way to full day again.... Is it bad to have that long of a photoperiod? I have no observed ill effects, the coloration of my corals and nems is perfect and my purple coralline algae is like exploding everywhere. What do you think? Thanks!

10/03/2016, 04:48 AM	#4
Ron Reefman Registered Member Join Date: Jul 2009 Location: Cape Coral, FL Posts: 10,431	You are correct that in the tropics the sun is up for 12 to14 hours However, in the tropics, actually anywhere underwater, the early to mid-morning light and late afternoon to sunset light hits the water at such a steep angle that it's strenght (PAR) is dramatically reduced on all but the radically shallow reefs (1 to 2 feet). That is why most zooxanthellae only do 4 to 6 hours of photosynthesis during the day and then shut down even if they get more high PAR light in our aquariums. For hundreds of thousands of years the have received the same amount of strong sun (9 or 10am to 3 or 4pm) so they have evolved genetically to use that sun. Before and after the PAR just isn't high enough. Water reduces PAR very quickly. And sunlight coming in at a steep angle has to travel through 2, 3 even 4 times more water before it reaches the corals on the bottom. This reduces the PAR so much that it is unuseable by the zooxanthellae. It may look good to our eyes, but our eyes can dilate and function in dimmer light. Corals don't have that option, their only choice is high PAR levels of 4 to 6 hours of midday sun. On the other hand, extra long high light photo periods have not been shown to have any negative impact on corals in our tank. They do not get much, if any, benefit, but no negative effects either. The zooxanthellae do require a 4 to 6 hour low light or lights out period. But as long as the light is low enough PAR that the zooxanthellae shuts down it's photosynthetic processes, that's really all that is needed. __________________ The good thing about science is that it's true whether or not you believe in it. (Neil deGrasse Tyson) Visit my build thread http://www.reefcentral.com/forums/showthread.php?t=2593017

10/09/2016, 05:10 AM	#6
Ron Reefman Registered Member Join Date: Jul 2009 Location: Cape Coral, FL Posts: 10,431	It's been some time since I read about photoperiods and photosynthesis time frames. If/when you find something, please share it. I'd appreciate a refresher. __________________ The good thing about science is that it's true whether or not you believe in it. (Neil deGrasse Tyson) Visit my build thread http://www.reefcentral.com/forums/showthread.php?t=2593017

10/02/2016, 03:50 PM	#2
Half Vaped Registered Member Join Date: Apr 2016 Posts: 401	Because of my unusual work hours (1 p.m. to 1 a.m.), I keep my actinics on for 15 hours a day: 11 a.m. to 2 a.m. so that I can watch and take care of my tank before and after work. Actually the actinics are shut off for three hours during the afternoon when all the blue-white lights are on, to save electricity, reducing overheating and save bulb life. My actinics are 2x 80W bulbs and I have two sets of 4x 80W bulbs for my blue-white lights (mixture of ATI Blue Plus, Actinic Plus, Coral Plus and Purple Plus). One set of blue-whites are on for 1 p.m. to 11 p.m. The other set is on for 2:30 p.m. to 12:30 a.m. Each set of blue-whites on the DT have a set of lights on the opposite photo-schedule in the refugium sump. I have had this photoperiod for about a year and a half and noticed no ill effects on anything. I have clams, acros, SPS, LPS and softies all growing--some fast, others, not so much. Some of my SPS are browned out, which may be attributed to the long photoperiod; I'm not sure. I think you should be fine. Just be careful when acclimating new corals. I always place new corals on the bottom for a few days to let them get used to the lighting.

10/02/2016, 06:31 PM	#3
BlackIceClowns Registered Member Join Date: Sep 2016 Location: New York Posts: 11	I don't have any SPS and I'm going to leave that until after med school, but I have Hammer Coral, Green Goniopora, Acans, and I have a RBTA and a maxi mini.. they all love the light I give them.. I mean I always could get a metal halide and put it on for 4-6 hours in the middle of the day for the super intense midday "sun", but for now they love it. Just seein what other people think of the long period

10/08/2016, 03:13 PM	#5
BlackIceClowns Registered Member Join Date: Sep 2016 Location: New York Posts: 11	Very helpful, thank you, you've turned me onto another search for papers about this. Thank you.