Purple Nana Color Change

[zulu_principle]

"that lighting only has a small role in color of SPS"

Please explain more.............



Wendell

[Aquattro]

way too long of an explanation, primarily based on limited experience and many hours of reading Eric's articles. I think though, that to expect lighting alone to control the color of a coral is being naive. Do you disagree?

[zulu_principle]

It was the "small" part that i found interesting............

Scientifically, your guess is as good as mine.


Wendell

[Aquattro]

Although I can't prove it, I believe small to be quite accurate!!

To explain is difficult, but I think that there are so many factors affecting color, that lighting becomes a small part. What type of fish you have and what the eat dictate, to a degree, what food is available for the corals. This fish excretment contains varying amino acids, organic and nitrogenous compounds. These "ingredients" will play a role in the production of pigment proteins within the coral tissue. This will be similar to dissolved organics in the water column also.
I have witnessed alkalinity affect coloration also. When I bumped my alk up from high 2s, to mid 4s, I noticed a color shift in many corals. I confirmed this with other hobbyists.
I believe flow can affect coloration, as can temperature. Reaction rates within the tissue will be dependant on temp(and enzymes, etc...negligble for our purpose).
I believe lighting intensity (wattage and/or proximity of bulb) as well as duration of the light energy will affect the coral, but I don't feel color temp has a big impact.

Unfortunately you'll find as many "experts" that agree with this as don't.
Like I said, I can't prove it scientifically, but my observations are common among many others in the hobby.

[StirCrazy]

for the record I also agree with brad.. I would say lighting its self is important (intensity and such) but color temp isn't realy that important.
I have also been finding that you can still get awsome growth and color from shorter photo periods, but I want to do some more testing on that befor I go off on that.

Steve

[Delphinus]

For the most part I quite agree with Brad, with one itty-bitty tiny exception:

Originally Posted by reef_raf

but I don't feel color temp has a big impact.

I think this could quite possibly be true for many corals if not the majority, but certainly not all of them.

I have an acropora, the first one I ever owned which has been with me through thick and thin and lived through temperature disasters, fresh water float valve disasters, high nitrate disasters, etc. etc. Anyways when it is under 10000K halide lights (175W), it is an amazing colour of purple with green highlights. Under 6500K halide lights supplemented with actinics .... it is pure brown. Oh, the actinics give it a greenish tint but take away the actinics and all you have is a ... coral the colour of poo. Moving it to under the Iwasaki's is the biggest mistake I ever made in terms of this one corals colour. Other corals in the tank have nice colouration, in particular I'm very happy with the pink/purple of my cats paw and the yellow of my cap, but come to think of it I also have a yellow acro which is slowly turning into the colour of poo. I've still saving my meager pennies to switch to Radiums when the Iwasaki's are spent, we'll see where things go after that.

I will try to see if I can later post some pictures of the brown acro in one tank, and the keen purple frags thereof that are in a different tank that is lit by nothing but 10K/175's.

[Aquattro]

Tony, keep in mind that switching color temp bulbs also results in changes of PAR values. A 400w 65k is a LOT brighter than a 400w 20k bulb.
Just a note also, brown (poo) may be the natural(healthy) color of that coral. Purple may be a defense to the properties of the previous light.

And on the Radiums, I wouldn't recommend them if you're only desiring a color change in corals. I have to say that I don't have any net change in my tank after switching; some got a bit nicer, some got a bit not nicer(lost for words there!!). I still prefer the look of the Radiums for my viewing pleasure, but they didn't transform my tank to colorworld!!

[Delphinus]

Ah, but the defense from light intensity by producing pigmentation is what we're (generally) hoping to acheive in our coral gardens. Natural, in this case, can be somewhat subjective. If the same coral is found at 6' of depth and 25' of depth, I would expect the colours to be different yet both still "natural aka healthy."

Frags of this coral that I have given away to others, some with bluer lights, and some with just more intense lights, the coral just turned fluorescent yellow. In the case of this coral, I beleive the purple is in fact the natural colour, and yellow is the "ok this is too much" mechanism, and brown is just ... well it's not unhealthy but it's not very pretty to look at, either. Purple is how it's been for me for 4 years prior to last year when I moved it into my "SPS tank." Previously I had grown 1/2" frags of it to 10" monsters of it. It grows like a total weed under 10k's. 10K's appears to be the best light for this one. Just my observation.

I'm not completely disagreeing with you here.. I agree with everything else you said. I'm just asserting my own opinion that colour temperature is not wholly irrelevant. Like with other things, it plays a role. Whether that role would be "small" or "substantial" is perhaps open to debate, but all I really want to assert is it's "non-zero."

BTW, I'm not looking for Radiums to be a colourworld, I just want to try them for my own viewing pleasure. I can't form an opinion on lights until I've tried them for at least 6-12 months.

I've tried several different combos and my personal favourite, of what I've tried that is, is still the 10k's. But I want a share of the radium pie too (so that I can form my own opinion)! You guys get all the cool toys, and then pooh-pooh the rest of us when we try to jump on the bandwagon. That ain't fair!!!

PS. OTOH, I certainly don't disagree that people get far too hung up on colour temperature. There isn't, IMO, one all-encompassing light temperature, the "OneTrueLightTemperature(tm)." The trick is to find what you like, and work with it. Some things just respond differently to different things, so you find what you have, find out how it responds, then run with the one that seems to give the results that make you happiest. For some it's 6500K's, some 10K's, some 12K's, and some Radiums. By no means am I putting Radiums over all my tanks .... I have no desire to change away from 10K's over my anemone tanks, for example. Very happy with the results there.

[Aquattro]

Tony, you are correct. Color temp does play a role...sometimes. All things play some role sometimes on some corals, so no rules are applicable. Makes it that much more fun!!

As for the radiums, I would certainly not try to talk you out of it....I love the color. I also have not experienced a lack of growth using them and would not consider (at this point) going to anything else.