Lighting Wavelengths
- Thread starter snaza
- Start date
redfishsc
New member
I'm wondering the same thing.
BTW I found what appears to be the graph for a Fiji Purple, although the website says they had great difficulty finding it and can't recall where they got this. Therefore is sounds "questionable" in that regard (and note that the graph is very smooth, as if "hand drawn") HOWEVER I DO NOT doubt the honesty of the website..... I am only curious as to whether his source is a true spectral graph of the FP bulb.
http://www.practicalcoralfarming.com/t5spectrums.html
BTW I found what appears to be the graph for a Fiji Purple, although the website says they had great difficulty finding it and can't recall where they got this. Therefore is sounds "questionable" in that regard (and note that the graph is very smooth, as if "hand drawn") HOWEVER I DO NOT doubt the honesty of the website..... I am only curious as to whether his source is a true spectral graph of the FP bulb.
http://www.practicalcoralfarming.com/t5spectrums.html
Todd March
Premium Member
<a href=showthread.php?s=&postid=14519949#post14519949 target=_blank>Originally posted</a> by redfishsc
I'm wondering the same thing.
BTW I found what appears to be the graph for a Fiji Purple, although the website says they had great difficulty finding it and can't recall where they got this. Therefore is sounds "questionable" in that regard (and note that the graph is very smooth, as if "hand drawn") HOWEVER I DO NOT doubt the honesty of the website..... I am only curious as to whether his source is a true spectral graph of the FP bulb.
http://www.practicalcoralfarming.com/t5spectrums.html
After reading lots of these spectral graphs, and living with the Fiji Purple, this graph looks REAL accurate to me. You can see the actinic spike (and even UV, which REALLY accounts for the strong fluorescing effect these bulbs have on GFP's!) these bulbs have, the blue, the touch of green which saves them from being too weird looking, and of course the red...
Glad to see thisâ€"thanks for posting and for the link, that's great reading...
Last edited:
MCsaxmaster
New member
Hi guys,
While the spectrum above is not unreasonable, there's no way to tell if it's correct just by the look of the bulb. Combining blue and red light will give you magenta/purplish, but so does purple light in the absense of other wavelengths. A light that gives off purple photons can have the same color (to the human eye) as one that gives off the right combination of blue and red
cj
While the spectrum above is not unreasonable, there's no way to tell if it's correct just by the look of the bulb. Combining blue and red light will give you magenta/purplish, but so does purple light in the absense of other wavelengths. A light that gives off purple photons can have the same color (to the human eye) as one that gives off the right combination of blue and red
cj
fijiblue
Active member
Hey Snaza- Things have been put on hold with my daughter being born back in December (two kids, work and a side business don't leave much time for the tank
) I passed my info to Dana and we have talked about it a few times. From our conversations, it sounds like he is making some exciting progress with the T5 study...
The Grim Reefer
Ready for some NOBALL!!!
This is a combination of a Blue Plus and a UVL 75/25 which is a little less pink than the Fiji. It's my dusk/dawn combo so the lamps are not close together. It gives a cool effect, bright kinda sunset purple in the lower front and an eerie blue in the upper rear. I LIKE IT!
The Fiji would make the front a little brighter and a tad more red. If the lamps were mixed together It would be a purple color. I would probably do a 2 to 1 Blue Plus to Fiji Mix.
This is 4 Blue Plus, 1 UVL 75/25 and 1 UVL Actinic White. Probably a little less red than 2 Fiji's would provide but not by much.
In the dry-land world, many plants growing in subdued light will, over time, go darker in lower light to absorb more light and go lighter in brighter conditions. It was explained to me that as long as the light is within the range of the plant, they'll self-adjust this way to match the light conditions, adjusting to the location and even the season.
Perhaps some corals do this?
Yours now are lots-of-light = lots-of-growth, but are now getting more than they need so could they be going lighter to absorb less?
DheereCrossing
New member
Try leaving the lighting the same but now increasing flow to raise the photosynthetic threshold. Could be a good experiment if nothing else.
Just reading this article where it lists the saturation point of SPS
http://www.advancedaquarist.com/200...iew?searchterm=
Anyway it appears that the saturation of most is about 200-300 PAR. If thats the case then why do so many tanks have SPS that get 500-1000 PAR. Is that just a waste or am i missing something?
Thanks
http://www.advancedaquarist.com/200...iew?searchterm=
Anyway it appears that the saturation of most is about 200-300 PAR. If thats the case then why do so many tanks have SPS that get 500-1000 PAR. Is that just a waste or am i missing something?
Thanks
TulsaReefer
New member
I would say that unless you have corals that really need that level (and there are very few) then it's probably a waste. I attended conference last fall with Dr. Sanjay Joshi and talking with him he basically said that quite a few people tend to over light their tanks.
MCsaxmaster
New member
The intensity of light required to reach photosaturation is highly variable among corals depending on the coral species, the type of zooxanthellae the coral is hosting, photoacclimation, and likely individual differences among genetically distinct individuals.
For example, due to photoacclimation Stylophora pistillata collected from the same reef at a couple of meters depth and ~30 m depth have been found to reach photosaturation at ~400 and 80 umol photons/m2/s, respectively (early work by Muscatine et al.).
However, all of this gets much, much more complicated when considering branching corals as compared to massive corals, or when comparing tissues in coenosarc and different spots of the corallite in corals. Branching corals inherently self-shade. Most of the light gets absorbed in the outer tissues and, sometimes within a few cm into the colony, you're down to light so dim it can barely sustain photosynthesis. For instance, we determined the light extinction coeficient in a branching Caribbean coral, Madracis mirabilis (rather similar to Stylophora or Pocillopora), in the field a couple of summers ago. At ~10 m depth the light intensity on a clear day was ~350 umol photons/m2/s during midday. Within 5-7 cm the light intensity inside a colony was down to less than 5 umol photons/m2/s--too little to support normal photosynthesis. Not surprisingly, below 5-7 cm at this depth the tissues naturally die back.
A lot of corals, regardless of growth form, will have a combination of very blanched and darker tissues in very shallow water. The tissues that are most exposed to sunlight tend to be very light, almost bleachy. At the very high light levels those corals often see during midday very little photosynthetic pigment is needed, and much of it gets destroyed daily anyway. In the deeper tissues (and remember, we're talking about around corallites--a few mm or less difference) the tissues are much darker and have much more photosynthetic pigment. These deeper tissues are more shaded. They require more photosynthetic pigments to capture sufficient light, and less pigment is destroyed daily by excessive light.
I suppose the point I'm really trying to make is that one size does not fit all, these issues are far from simple, and generalization can easily lead to overgeneralization. In particular, assuming that light tolerances or needs are similar among "sps" corals is totally and completely wrong. Different species of corals that we would call "sps" corals are tolerant of both the highest and lowest light levels generally tolerated by photosynthetic corals. Designations like "sps" mean absolutely squat about a corals' light needs or tolerances...really.
For most corals I think 200-300 umol photons/m2/s is a reasonable target light intensity. Some would be fried by that and some would be undersaturated but many will do quite well indeed. As for higher light intensity of say 500 umol photons/m2/s: many aquaria with strong lights probably have a few spots in the tank that bright, but very few tanks have more than small portion of the tank that bright. As for 1000 umol photons/m2/s: while I'm sure they exist, VERY few tanks are getting that kind of intensity essentially anywhere in the tank. While many corals can tolerate intensities that high for a few hours a day, it can cause significant photoinhibition in the outer tissues in many corals. That would not be a wise regime in captivity
Chris
Awesome Chris. thanks heaps. After reading that i now have a new question for you, If thats ok 
Just say I have 2 tanks, 1 of them has 2 x the light of the other. If i ran the lower light tank for 2 times as long would saturation be equal.
ie. Tank A has 500par for 5 hours but Tank B has 250par for 10 hours. would that be equal?
Just say I have 2 tanks, 1 of them has 2 x the light of the other. If i ran the lower light tank for 2 times as long would saturation be equal.
ie. Tank A has 500par for 5 hours but Tank B has 250par for 10 hours. would that be equal?
Last edited:
greenbean36191
Premium Member
No. Photosynthesis is essentially instantaneous, so the photoperiod has nothing to do with saturation.
If in your example the onset of saturation for your coral starts at 300 umol, in tank A the coral will be saturated the minute you turn on the light and saturation will never occur in tank B regardless of how long you leave the light on.
If in your example the onset of saturation for your coral starts at 300 umol, in tank A the coral will be saturated the minute you turn on the light and saturation will never occur in tank B regardless of how long you leave the light on.
The Grim Reefer
Ready for some NOBALL!!!
So maybe one of you brainy guys with or studying to get letters after your name can offer your thoughts on this,
Is it possible one of the reasons SPS tanks are thought to need so much flow because the corals are receiving too much light and high flow tends to lessen the Photoinhibition?
Is it possible one of the reasons SPS tanks are thought to need so much flow because the corals are receiving too much light and high flow tends to lessen the Photoinhibition?
greenbean36191
Premium Member
High flow doesn't lessen the photoinhibition- it lowers oxidative stress from high levels of photosynthesis. And yes, the need for high levels of flow is related to the high levels of light the corals are receiving.
