Colors - sunlight only vs MH only

[karimwassef]

For about an hour a day, some of my coral's get sunlight.

I was comparing the color under sunlight vs. my double ended 400W MH 12000K

Here's sunlight only:
<a href="http://s1062.photobucket.com/user/karimwassef/media/958719F6-D407-4868-8ACC-AFEF30732B0F_zpsmv9vltl4.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/958719F6-D407-4868-8ACC-AFEF30732B0F_zpsmv9vltl4.jpg" border="0" alt=" photo 958719F6-D407-4868-8ACC-AFEF30732B0F_zpsmv9vltl4.jpg"/></a>

Here's MH only:
<a href="http://s1062.photobucket.com/user/karimwassef/media/E5D35348-AF97-4394-9863-EF65F393F36C_zpsw1wvpbfd.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/E5D35348-AF97-4394-9863-EF65F393F36C_zpsw1wvpbfd.jpg" border="0" alt=" photo E5D35348-AF97-4394-9863-EF65F393F36C_zpsw1wvpbfd.jpg"/></a>

So what's missing in my MH that's hiding the pink in the coral tips and making them look blue?

 

[Eastone]

I've found that pink-purple colours come out more pronounced under lower kelvin lighting, and the blues similarly so under higher kelvin lighting.

 

[karimwassef]

But when snorkeling, I see very pronounced and near iridescent blues.

Hmmm

 

[karimwassef]

Ok. Thinking through this. The time when the sunlight gets to the tank is around sunset. That aligns with the lower kelvin rating.

I usually snorkel closer to midday with some cloud cover that usually aligns with a higher kelvin.

I wonder if a continuous video of a coral in the wild would really show a gradual daily color change.

 

[karimwassef]

Maybe we should emulate the color mix in LEDs over the day's hours. 2500K - 12000K - 2500K

 

[Eastone]

Ok. Thinking through this. The time when the sunlight gets to the tank is around sunset. That aligns with the lower kelvin rating.

I usually snorkel closer to midday with some cloud cover that usually aligns with a higher kelvin.

I wonder if a continuous video of a coral in the wild would really show a gradual daily color change.

In my personal experience, the bluer corals are usually slightly deeper - at least about 5-10 meters (I've only had limited experience snorkeling on a reef, however) with the pink, green and purple corals being closer to the surface. I think this is a factor of the water filtering out wavelengths of light and resulting in a relationship of kelvin increasing with depth, so the deeper you go the higher K value the light has.

This effect wouldn't be nearly as pronounced in a captive reef and may explain the colour difference in the same coral with similar environment you're experiencing.

My light schedule runs from around 18-20000k in the morning through to about 6000 midday and back up in the evening. This is to emulate natural light, where diffracted indirect light in the morning and evening would be in the bluer spectrum due to the increased distance traveled through the water column in nature, despite being if a lower kelvin rating. The result I see is strong pink and purple colouration without sacrificing my blues and iridescent colours either, and being able to maintain strong growth throughout. I do run an exceptionally long photoperiod with 8 hours at 100% and an additional 7 at 50% blue

 

[karimwassef]

My light schedule runs from around 18-20000k in the morning through to about 6000 midday and back up in the evening. This is to emulate natural light, where diffracted indirect light in the morning and evening would be in the bluer spectrum due to the increased distance traveled through the water column in nature, despite being if a lower kelvin rating. The result I see is strong pink and purple colouration without sacrificing my blues and iridescent colours either, and being able to maintain strong growth throughout. I do run an exceptionally long photoperiod with 8 hours at 100% and an additional 7 at 50% blue

I run blue/white/uv mix as well. I think natural light is the opposite though. red-white-blue-white-red