My experience with too much red lighting

[rockskimmerflow]

I've got a pocillopora coral in my tank that due to shading from rock of the sunlight that comes in through the back window, only the half of the colony close to the front glass gets sunlight, the back half only gets my weak mostly blue LEDs.

The sunlit half has now grown much faster, and is significantly taller then the back half. The sunlit half, however is brown and the back half has better fluorescence. That is as expected.
A while back the colony bleached - I let phosphate go to zero while nitrates were elevated, full recovery was made with dosing phosphate. Rather I should say part of the colony was bleached, I just went back and pulled up the pictures....

... it of course is the sunlit part that bleached, and there was no bleaching in the back half (far right in pic) that receives no sunlight, only much less light from blue heavy LED.

Interesting observations there. Not sure that the red light had any effect whatsoever on the bleaching you observed -I would surmise it was the overall quantity of light that accelerated the bleaching in the sunlit portion compared to the more weakly illuminated LED side. The best analogy I can think of to what likely occurred is if you took a car engine and filled it full of gas but let all the coolant drain out of the system. Imagine revving it to max rpm and running it til it blew up. It would happen significantly faster than if you let the car idle with the same imminent overheating result. The light exposure is like a foot on the throttle. With less light intensity the inevitable bleaching due to phosphate starvation would have occurred much slower in the LED side. Makes perfect sense the sunlit side bleached out faster. Glad to hear you were able to ID the problem and correct course.

 

[John3]

AB+ is a schedule that can be run on a lot of the newer led lights where all color channels are adjustable. This schedule mimics a T5 light output. It’s a proven winner but at the very least a good starting point.

 

[KrisReef]

Nice thread.
I think there are a lot of articles available that describe light absorption on the natural reef. This one mentions that 35% of the 'red' spectrum is lost in the first meter of seawater. Blue penetrates furthest.
https://www.advancedaquarist.com/2013/12/lighting

The reg veg light was designed to grow terrestrial plants. Plant growers switch the spectrum and photo period to produce flowers.

A long time ago a bulb sales person told me that their specific (un-named here) bulb was not good for aquariums because it was high in the red spectrum and would grow algae really well.

 

[taricha]

Not sure that the red light had any effect whatsoever on the bleaching you observed -I would surmise it was the overall quantity of light...

Totally. This is not a clean experiment - this thread is anecdotal observations. Our tanks always have several variables at once.
And good explanation - more light definitely drives everything harder, increasing risks if nutrients are unbalanced. Or maybe the spectrum did contribute somewhat.
Hopefully observations, though not rigorous can still inform our setups when we do experiments.

 

[Hans-Werner]

In my eyes it is not that easy to say "red light" and "blue light" because the physiological control is done either mainly by blue light sensors cryptochrome and phototropin or by the red-far red-system of phytochrome, maybe in cooperation with cryptochrome or phototropin. The sensitivity especially of phytochrome is of narrow bandwidth.

While phytochrome is like a switch that is controlled by two specific wavelengths the blue light sensors works with just one wavelength and measure intensity of this specific wavelength. The highest sensitivity of blue light sensors is usually around 450 nm but may be shifted a bit to shorter or longer wavelengths.

At least in land plants and most algae where phytochrome was found 650 - 670 nm red light is the signal for strong light while far red light of 705 - 740 nm is the signal for weak light.

Since zooxanthellae contain phytochrome the red light with its maximum at 650 nm used by Tim Wijgerde et al. is a strong signal for strong light. The reaction of the zooxanthellae is that they are regulating down their photosynthetic apparatus which is confirmed by the results of Tim Wijgerde et al..

In my experience different corals can behave quite different. While Tim Wijgerde et al. used Stylophora pistillata, the Guinea pig among the corals, other species or morphs of corals may show quite different reactions. Especially the red color morphs of plate forming Montipora spp. seem to be quite sensitive to blue light and frequently show loss of color, bleaching and necrosis when too much blue light (e. g. new or different metal halide bulb) is added. Also when metal halides are changed against led which emit much more 450 nm blue light corals may show some bleaching and a phase of adaptation.

 

[Dana Riddle]

Yes, I do. LOL. Agreed that a lot more research is needed.

Not sure it ever "fair" to judge by extremes as to effects..
"Whole is greater than the sum of it parts" seems to apply often..

As to MH and tubes.. even high K and bluish.. there is a fair amount of red.. well needs to be defined what a "lot" is..
You may recognize this:

 

[Dana Riddle]

I am aware of the research indications of red light's detrimental effects. In my case it was not pure red light or even dominantly red since the fixture housed 7 other aquarium type lamps, so that may be why I had no observed negative results.

There was a purple S. Pistillata in that tank that showed no issue when the red lamp was in use. I never did a PAR test on that tank. Fixture is an 8x54w Sunblaze. Other lamps were ATI 4x BP, 2x TA, 1x ABS. I replaced the red with a different copper colored Horticulture lamp that had a really interesting 400-420nm + 660-700nm spectral profile. That has been in place instead of the pure red for the last 5 months or so with good results as well.

Tank is 7'x3' with roughly 12 inch water depth with about 4 to 8 inch average water over the corals.

Will look at the brand on the red lamp when I have time to dig it out of whatever case of bulbs I stuck it into.

Thanks! I'll look into this when I get a chance. Appreciate the reply and info!

 

[Velcro]

I would like any science and research in the aquarium hobby to take the same approach as every other true science and assume that nature is correct until proven otherwise. The large amount of red in the sun is the proof... until there are peer reviewed, encompassing testing and research. Until we do this, then I will still consider what we see with lighting as pseudo-science still.

If you want to argue that red light alone is a problem, then fine... but the OP is not talking about just illuminating with red light but rather as part of a fuller spectrum. Having an amount of red at least in the same proportion as sunlight is not an issue.

Except in nature that red light is quickly filtered out with increasing depth, while tanks are much more shallow.

 

[oreo54]

At 1M of depth the light contains roughly 25% orange to red.
25% of just red at surface guessitimate.
Would prefer surface % but not handy atm and this is just a thought exercise and BROAD.
Surface "PAR" can reach 2000.

Using that 2000 number even 90% decrease in red is 200 PAR.
99% decrease is 20PAR.
Roughly this would occur at 30+Meters and prob 5% @ 25M
5% of 2000 is 100 PAR..
Granted 2000+ PAR is peak but take say a daily average of 1000.
Or even 500....

How much "red" is in reef lights expressed in PAR? Red and only red?
Radion XR15 gen 4 has 23 diodes 2 deep red, 4 cool white and 1 warm white..
Guessing at total red content is like 1/5 of the PAR at full..which few run btw.
Lets guess at about 700 PAr at the surface.. and out of that 54 is red.
Lets just say equiv to 27M deep in the ocean at high noon..
You should get the drift...
NOTE: just napkin scribbles and prone to errors and does not tke into account 12hr cont. steady vs daily natural fluctuations.

Yes DEEP water has very little to zero red relatively speaking.. but the point is you need to look at absolute numbers..

Feel free to point out errors, really did this roughly..and just for discussion.

 

[Dana Riddle]

Let's refine this a bit. The action spectrum chart of the Favia coral describes the radiation absorbed for photosynthesis. Note that some red wavelengths are as efficient in promoting photosynthesis as those generally considered to be 'junk' wavelengths (yellow and orange, for instance.) Then look at the reduction of those wavelengths in 'clear' seawater (Jerlov Oceanic Type I.)

 

[oreo54]

But I need a better pie chart..

red "content" is fairly flat in the 600-700nm range.. Fairly..
well w in a slope of 10%..Except for 2 atm absorption dips at 690 and 650-ish.
(see chart)
https://www.avantes.com/application...ar-irradiance-and-solar-uv-field-measurements
Divide 500 by the 5 bands and multiply by the percentages:
100 x .79 = 79 PAR of 600 nm light at 1M
100 x .74 = 74 @ 625
70
66
38

327 total.. from 500
That's 35% reduction overall.
Which roughly fits w/ the 2 pie charts.

Good enough for gov work..
concept is fine..


Using the 2000 "PAR" sunlight figure and 25% that being "red" w/ out breaking it out all one can say, at this point it contains 500 PAR of red light from 600-700nm.

Will clean it up a bit.
Percent by wavelength doesn't help w/o absolutes..
One can assume a fair bit like above.
Still is like 300 PAR of red light..

 

[oreo54]

Dang.. errors..(prob not the only one.. )
58 not 38 @ 700
347 out of 500-ish
70% of daylight red at 1M

Corollary.. How much PAR do you get from a 3W red diode at 3ft?

 

[User1]

In the pie chart above isn't Green-Blue the same as Blue-Green? Combine the two and make the piece of pie larger unless I'm missing something.

 

[oreo54]

dividing by blue- green.. green-blue is just a choice..
"color" is a human construct anyways.
There is only energy..
<50% green or> 50% green I assume..

 

[Dana Riddle]

In the pie chart above isn't Green-Blue the same as Blue-Green? Combine the two and make the piece of pie larger unless I'm missing something.

Depends upon your reference for the breakout of spectra. I used an ancient college biology text for that chart.

 

[Dana Riddle]

This debate could go on forever. I think my time, as far as this thread goes, could be better spent designing an experiment to examine effects of red light with some equipment I haven't used before in this respect. I will use the chlorophyll meter, PAM fluorometer, PUR device, quantum meter, etc in this examination. Will get started after I get the speaking engagements out of the way (late October.)

 

[dz6t]

It is a misconception to consider MH as a full”er” spectrum light source than premium LED in the visible light regions. But MH has UV and IR which LED lacks.
The popular 250w Radium Metal Halide is not similar to sunlight. It is not even close. Also metal halide is not a true black body light source as the sun is.

 

[Brew12]

This debate could go on forever. I think my time, as far as this thread goes, could be better spent designing an experiment to examine effects of red light with some equipment I haven't used before in this respect. I will use the chlorophyll meter, PAM fluorometer, PUR device, quantum meter, etc in this examination. Will get started after I get the speaking engagements out of the way (late October.)

I'm looking forward to the results!

 

[oreo54]

• • Violet: 400 - 430 nm
  • Blue: 431 - 480 nm
  • Green-Blue: 481 - 490 nm
  • Blue-Green: 491 - 510 nm
  • Green: 511 - 530 nm
  • Yellow-Green: 531 - 570 nm
  • Yellow: 571 - 580 nm
  • Orange: 581 - 600 nm
  • Red: 601 - 700 nm

  [*]

Error?

• Green-Blue: 481 - 490 nm
• Blue-Green: 491 - 510 nm

or

• Blue-Green: 481 - 490 nm
• Green-Blue: 491 - 510 nm
• 
  
• .. sorry..it's an illness..

 

[dz6t]

The pie chart is for sunlight above water surface, not the spectrum under water at various depth.