We all want that pop in our tank and for that we use more blue and red not to mention actinics.
Good thing is that I see more and more tanks using just a regular 10K daylight bulb in the T5 combo.
Even LED's going more clear Daylight mix.
Par is just a number to go by no matter what combo of lighting you use.
Lets ask out own expert
@saltyfilmfolks
You are correct sir.
how rare
so is
@Dingo
But in reality it is a terrible measure of the quality of light that corals are getting.
If you have a completely blue washed tank you might have really high PAR strictly due to the amount of blue being emitted into the tank. However, this doesn't mean the light is right though
correct. and a par meter can be fooled. quite easily. like many things its up to us to know how to use the tool.
I spoke to a member here recently with coral probs and he said he had 250 par. but the light was 30% white and 75% blue.
well yes the corals probably dont like 35,000k.
Something just hit me.....you say PAR of 400 with red light....but did you measure that PAR value at the depth of the corals. If I remember correctly, I was told that red disappears within the first three inches of ocean water!
yes. is quickly absorbed.
but a meter will register high par on a single spectrum of high intensity.
and although some red is visually lacking its a longer wavelength than the others and does actually penetrate resulting in the bit of red we see in "optimal reef light charts". and likely what spurs so many debates amongst science as to its use by the coral.
I guess I am wondering why you state that the fluorescent colors of corals are a an indication of stress. I thought that it was scientifically unclear as to why corals are fluorescent. Can you expand on this?
book is being rewritten now that fish also glow.
IMO monkeys have bad eyes. its always bright where they live. A mantis shrimp would probably know.
Stress can be interpreted differently in this situation.
Not stress as in "about to die"
But rather stress as in "not the preferred wavelength" so therefore the coral must perform more work to cascade the electrons down the visilble light scale through re-emittance and reuptake until they reach the preferred wavelength.
its sunscreen according to Dana. and also camouflage and likeley feeding tools. and can be considered a stress event as its more prominent when Photosynthesis shuts down.
why they have color period is a good question. we know why berries are red and flowers have color. I would assume corals have color for the same reasons.
thats said, the same coral can and does grow in the shallows and and depths.
So PUR. and how a corl figures out what it wants.
A coral at the surface is getting an even spectrum of 5600k. 15ft down its 10,000k. 20ft 20k. also each depth is a lower and lower Par.
Does it look a bit different, probably. esp if it gets pars higher than the 350 dana suggests. OR is only getting wavelengths that stimulate specific carotenoids and producing only specific tints as a result of "uneven tanning"
if were on a north facing slope w less direct sun its color temperature would actually be cooler. but it still grows. would it look the same ? not sure, but probably.
but here's this.
Take some coral and put it under a 48,oook Phillips led from home depot. Check that the spectrum is fairly even( like daylight), with a spectrometer. (a par lux test would be fun too)
put it on the corals and see what happens.
Hint. It grows corals perfectly.
none of the corals after a year or more looked any different then ones I had seen before. Visually some appeared "dull" as there's no 420 somthing to make them "Pop" like under reef lighting.(remember they're engineered for aesthetics too). but were otherwise completely normal. especially once put under standard reef lights.
So. Id say the coral will take whats available and use it.
Its likely major overdose and under dose of specific frequency is where you get into trouble.
