Coral response to high lighting

[Brew12]

I see information on low lighting all of the time. I'm curious....

What is the expected coral response if lighting is too high?

Is there a way to determine if a specific color band is too high by looking at your coral?

 

[ihavecrabs]

Hmm, I've sometimes had slight bleaching (lightening of color) if I rush light acclimation. Interested to see what others have observed.

 

[8251reefer]

My Red Planet acro frag now looks like a white planet with maroon polyps. Definitely lightened up from the change in lighting from LFS to my tank. I lowered him and turned my lights down(Black boxes) to 40%B and min White channels. I'll see if that will allow his colors to come back...

 

[shred5]

Usually a coral will expel it zooxanthellae because of a increase in photosynthesis do to the increase light. This can produce more oxygen than the coral can handle.

Elevated temps cause the same thing.

 

[Fourstars]

Good question. I run halides and have found that most corals that people suggest need low light do fine and grow faster at higher light levels then is usually recommended, as long as they are acculmented slowly. I think light as revving up the engine. The problem with bleaching, which I have done more than once, is if you increase the light the corals will uptake nutrients/nitrate faster and if any of these are limited your corals will bleach? At least that's my thinking on the matter of light so far, might change tomorrow.

 

[shred5]

By J.E.N. Veron
Right out of his book Corals of the world good read.

http://coral.aims.gov.au/info/bleaching.jsp

 

[Fourstars]

Good read, but it applies to reefs not so much our tanks. I've also read that the addition of iodine helps corals expel the excess oxygen?

 

[shred5]

Good read, but it applies to reefs not so much our tanks. I've also read that the addition of iodine helps corals expel the excess oxygen?

It still happens in our tank all the time.. Bleaching is exceptionally common do to higher light especially jumps in light. It is the whole reason we acclimate corals by putting them lower in the tank or raising the light or putting mesh over the tank.

Some corals can adjust to higher light if you go slowly and sometimes they cant. Most corals have a tolerance to how much light they get... Leave your lights on accidentally over night once and watch your corals bleach.

Some corals have pigments and proteins they use for sunscreen to help block the light/UV and the can increase these pigments and proteins with time. Also coral given some time can shed some Zooxanthellae. Some corals will shrink to avoid light or pull polyps in and in lower light expand to make themselves bigger to absorb more light.

Some times people will try to slowly increase light for sps to force them to shed some zooxanthellae an increase pigments.

Corals have a tolerance to only so much light before they bleach and it varies between corals. A increase in light to fast in most cases leads too bleaching.

 

[Fourstars]

I think in the wild the issue is mostly with temperature increasing and I'm sure most of our reefs tanks are not even coming close the the par that a reef gets. My point is that on a reef things like nirate are not limited, or anything else for that matter.

 

[shred5]

I think in the wild the issue is mostly with temperature increasing and I'm sure most of our reefs tanks are not even coming close the the par that a reef gets. My point is that on a reef things like nirate are not limited, or anything else for that matter.

Think I answered the question or maybe I do not understand what your saying
What is the expected coral response if lighting is too high?

As far as spectral Dana Riddle would be able to answer that far better than anyone.

While it is true that lighting is less issues in the wild because corals grow where the light is right for them and temperature is more of a issue. The whole corals get more par in the ocean was started when we were on fluorescent lighting. Too many old myths still hang one. Leds can put out a lot of par that is why most do not run them at 100 percent. There have been some experts that think even though we do not hit the par of the sun but over the same period we give the corals more par. Until led came along we had no way to dim lighting so it was full on or full off. We did have the ability of turning off lamps. But the problem with the sun is it mainly hits one side of the coral in the morning and the other side in the evening. It is only at high noon for a short period and in our tanks it always is high noon. The angle that the sun hits the water in the morning and evenings end up refracting allot of the light plus wave action.. Also allot of corals are not shallow so light levels drop fast. Jason Fox said it in a video I saw our corals get less light in the wild than we think they do.

It is something that needs to be studied more to see if it true. Most studies that have been done with par have the sensor straight up but it is flawed. Any how the point is some people feel we give more par in our tank over the same period.

 

[Fourstars]

Good point, thank you for dispelling some of my myths. But corals response to light is more than just the photons hitting the Zooxanthellae, Its the conversion of light into energy isn't it? So the response is also a chemical one?

 

[jda]

Although the tool is not all that good, I can grow frags in a frag tank under 750-1200 PAR in full spectrum MH lighting for 8-10 hours a day. They do usually need a week or so of acclimation. They grow like crazy with great color. I do not HAVE to do this... most of them will have decent growth and color under 350-400 PAR. They do respond positively to more good light.

I think that the true full spectrum plays a big role. Riddle has written recently about red and far-red (IR) being able to help coral process lots of energy. Green is now seen as important as well. No doubt that yellow will be next.

For me, this is about quality before quantity. 500 PAR of crappy white LEDs will melt coral, yet the "same" spectrum on T5 or MH will thrive with twice the output.

I am not light guru, but it seems that peaks/bands can be at different levels as long as other levels are there to support them.

I have not seen a LED yet that can put out as much PAR as the sunlight, even in the USA - the amount of sunlight at the equator is much greater. The LED at 100% is a quality issue, not quantity. 2-3x the same PAR on MH will not destroy coral like under a LED. The atmosphere scatters the light - it is amazing how little shadows there are. If anybody believes that LEDs do not have bad spectrum and wants to test, I have 1000-1200 PAR of 6500K halide that I grow things under (mostly clams and acros), if anybody wants to put their LEDs up to 100% and a 6500k spectrum to compare then we can get some of the same frags and compare notes - nobody has taken me up on this yet.

The response? Good light? Bleaching and then slow/medium recovery. Bad light? Death from burnt tips on down.

 

[shred5]

Good point, thank you for dispelling some of my myths. But corals response to light is more than just the photons hitting the Zooxanthellae, Its the conversion of light into energy isn't it? So the response is also a chemical one?

Well I didn't dispel it totally I said what some experts think, I tend to believe it. They really should do more studies to verify it.

There are a lot of things that affect coral colors more than just light also but that is another topic.

 

[jda]

Corals can also develop colorful pigments to reflect high amounts of light. Who doesn't like more/different colors?

 

[saltyfilmfolks]

Some shrooms would visibly shrink the first day in some cases. Frogspawn lost color and became kinda transparent (expulsion) , my odd yellow acro (deep water I suspect )turns green, I turned a ricorida green in the sand bed (I suspect a Nm overdose there from the old lights). I changed lights and reduced intensity in that case , so inconclusive. My cyphasteria just plain bleached and died in two days when I moved a gorg that was shading it. It did turn a bit green in a couple spots before it croaked.

I just bought a red planet that’s quite pale from too much ligh (I know the vendor and tank) but still grew and encrusted. A deep water acro as well.

Some of my Xenia, palys , zoas branching montis , toadstool just don’t care.

Many I’ve obseved , mostly the lps chalice acan family , just stayed small. Once I lowered thier intensity, they grew quite well.

 

[jda]

This is a good post above... the species probably matters a lot. I have acropora, one Leng Sy monti and some Bounce and Jawbreaker shrooms that I grow to sell/trade. This is what all of my posts are based on.

 

[Sallstrom]

Here's two frags from the same mother colony. The first one has been in PAR 165 and the other one in 550. They live in the same water system. Fun to see how much different light conditions can do
No big difference in grown I think(haven't measured).

 

[Fourstars]

In the OP original post he asked "Is there a way to determine if a specific color band is too high by looking at your coral" is the OP asking about PAR or color temp? PAR is the intensity of visible wavelength from 400 to 700 nanometers so would a 20,000 bulb have the same PAR as a 5600 k, ANd does color temp have effect on growth?

 

[saltyfilmfolks]

In the OP original post he asked "Is there a way to determine if a specific color band is too high by looking at your coral" is the OP asking about PAR or color temp? PAR is the intensity of visible wavelength from 400 to 700 nanometers so would a 20,000 bulb have the same PAR as a 5600 k, ANd does color temp have effect on growth?

I short , if your at an lfs drooling on a coral, no. IMO

Color temp, kinda, 20k (and all others) can be mixed a number of ways.

I’m my Ricordia observation , I kinda think there was either a spike in a specific band , or not enough of another , IMO, most likely red. As that was in fashion when those lights were made.
I had two, one directly on the sand , so par overdose IMO , but the shaded one also greened but much less.
Many others in the tank were completely unaffected.


Fwiw, par is higher relative to intensity on a 56k bulb vs a 20k in general as the 56 has a higher amount of other colors corals don’t use , but plants do. Y&O.
Because Par meters aren’t just for coral.

 

[Brew12]

my odd yellow acro (deep water I suspect )turns green, I turned a ricorida green in the sand bed

This is one of the things behind my question. I run my lighting very "white" and it seems like all my non-red acro's tend to green on the sides that get the most light. Was wondering if there was a correlation.

In the OP original post he asked "Is there a way to determine if a specific color band is too high by looking at your coral" is the OP asking about PAR or color temp?

I was not asking about PAR since, as you point out, that is spectrum related. Since I do run my reds and greens very high, which has little impact on PAR, I was wondering if there are visual cues to look for.