Color spectrum for SPS

AdamNC · Aug 7, 2015

So my tank is doing good with the lighting I have, not looking for halide/t-5 vs led advice. Normally I run my highest at ch1 65% ch2 90%. So I wanted to take some pics and as you know with iPhones too much blue makes the pic look horrible. So I turned the whites up to 100% and the blues down to 50%. Looks more natural but I didn't like as much but my wife finally said" I really like it like that". She doesn't like all the florescence on the greens and oranges. I've heard most people run a higher blue but there are a few that run more white. Is there really a difference in coral health if I shift the spectrum a little bit to more white? ie: bring the blues down a bit and the whites up.

Nano sapiens · Aug 7, 2015

The short answer is 'yes' you can (within reason). You are basically going from a ~16000K towards a 10000k (or less) look. Natural sunlight just under the water surface is around 5500K as a reference.

'White' LEDs are really blue LEDs with specific coatings to produce other spectrum colors. So when you add more 'white' (while keeping your blue channel the same) you would be actually adding blue + other colors (the 'other colors' percentage depends on the type of 'white' LED).

Predicting coral health based on spectrum is tricky. Corals from shallow areas will likely be fine with the warmer spectrum, those from deeper waters my be more comfortable with a bluer spectrum. Any changes you make should be done slowly over at least a few weeks time to allow the corals to adapt.

AdamNC · Aug 7, 2015

yea I was counting on a slow acclimate but what I was not considering and thank you for bring up was that I think I do have some deeper, but not deep water corals. Bonsai, Hammer, Duncan and a Frogspawn.

rovster · Aug 7, 2015

I firmly believe in running at least part of your photoperiod in the whiter spectrum. I've got 4-5 hrs of about a 12k on my radions. Just take it easy because the white LEDs are INTENSE...

Chaz D · Aug 8, 2015

rovster said:
Just take it easy because the white LEDs are INTENSE...

How are the whites more "intense" than the blues?

rovster · Aug 8, 2015

Same way a daylight bulb is more intense than an actinic I suppose? It is pretty well know that turning up your white channels too high too fast is a sure way to fry your corals. I have no scientific evidence, just personal observation and here say...

Nano sapiens · Aug 8, 2015

Chaz D said:
How are the whites more "intense" than the blues?

Both can be 'intense' and provide a lot of PUR. The cooler the 'white' the more 'blue'. A 'cool white' LED, for example, is mostly blue spectrum while a 'warm white' LED has a lot less 'blue' and much more of the green/yellow/orange/red.

mcarroll · Jul 18, 2016

AdamNC said:
So my tank is doing good with the lighting I have

Could be a good reason not to change anything...this would get my vote.

AdamNC said:
Is there really a difference in coral health if I shift the spectrum a little bit to more white? ie: bring the blues down a bit and the whites up.

Yes, but the question isn't nearly that simple. Coral health is a summation of lots of factors, not limited to light, flow and nutrients reliably available.

Even just the factor of light is not just as simple as intensity....for example, at least some corals use specific colors of light (e.g. red) to judge their proximity to the surface. Surface light is wicked-stressfull, so they have to be able to know it's coming if/when they grow to the surface. The coral changes behavior in response to this light. In the aquatic setting, this changes in behavior is often negative. Ideal flow and nutrient factors make a big difference.