dusk dawn spectrum change and coral reaction

[LEGACYLINE]

I've been noticing when my dusk dawn (t5) kick on (two blue plus) the coral do not react well from the spectrum shift from daylight to all blue I run 3 blue plus 2 coral plus 1 purple plus for my daylight hours ..I did an experiment with changing the dusk dawn to one coral plus one blue plus so the spectrum doesn't change much though the day when ramping down and the corals seem to react better to that..is there any study that spectrum change affects coral through the day or is it best to keep a steady spectrum ? I know most people like all blue to show the coral off

 

[Flippers4pups]

I've been noticing when my dusk dawn (t5) kick on (two blue plus) the coral do not react well from the spectrum shift from daylight to all blue I run 3 blue plus 2 coral plus 1 purple plus for my daylight hours ..I did an experiment with changing the dusk dawn to one coral plus one blue plus so the spectrum doesn't change much though the day when ramping down and the corals seem to react better to that..is there any study that spectrum change affects coral through the day or is it best to keep a steady spectrum ? I know most people like all blue to show the coral off

This is as close as I know:

 

[LEGACYLINE]

Thanks for the video

 

[jda]

I would be shocked if there were any study that specifically addressed this. The dusk/dawn is for you, not the coral, so you can quit if you think that they are suffering... of if you like it, then tell them to "rub some dirt on their wounds" and get back into the game. You probably won't see too much troubleshooting with dusk/dawn since if anybody has issues, they just quit since it is not necessary whatsoever.

 

[LEGACYLINE]

Lol..yeah it's not a big deal either way just noticing they dont like it much ...might just be the intensity change also ..

 

[Dana Riddle]

I'm assuming the negative response is polyp retraction? Could be synergy of intensity/spectrum. The graph shows Photosynthetic Usable Radiation (PUR) of LEDs found in Orphek's Atlantik V4 luminaire - while not T5 lamps, it does suggest that PUR of T5s could be high as well.

 

[LEGACYLINE]

Thanks Dana ..and yes polyps retract when all blue lights are on ..this happens in the morning as well with all blue plus bulbs on they only come out when daylight bulbs kick on ..I know people that dont have problems all depends on water conditions etc..
But I just find my corals sps in general just don't respond well to all blue even though blue plus have a broader spectrum than just "blue" but that's just my tank ..I've tried running all blue / actinic lights in the past and they just didn't do well even though the par was good can you have to much pur to par ratio? I know people use all blue to color up and grow coral but my alkalinity and calcium demand dropped noticably which made me wonder why when par was in a good range 250 350 but again I know people have success with running all blue plus