Too much light?

[NatureNerd]

Okay, how do I know if I have too much light? I switched to 3 AI Sol Super Blues months ago on my 75g. Growth, and color, is better than I have ever had. I run these lights at 90% power and they are about 8" above the water. When I first got them, I ramped up slowly and was coming from MH's w/vho's.

A couple of my SPS's are very slowly moving to rich purple tips but very light pastel color everywhere else, almost like an ULNS tank that I have seen. I do not run low nutrient. These corals are not bleached. They seem very healthy with nice PE and fast growth. It is just a different look than I am used to. If I lowered the power levels or period would these pieces darken up on the bodies of the colonies?

Most of my colonies look great. Just a garf bonsai and a tricolor show this lightening.

Thanks!

 

[jamgar]

I was wondering the same thing with similer findings

 

[NatureNerd]

The pastel colors are nice but is this a symptom of too much. In all my research, I have never seen any warning of what to look for if you think you are supplying too much light. Yes, a quick change results in a rapid bleaching event but what about a slow change? Or is it even possible to provide too much light?

Anyone?

Example given:

 

[jamgar]

If you reach an photosynthetic inhibatory amount of PAR it can affect growth and color. It seems lightening of colors can be caused by multiple factors including non-stable water parameters, too little or too much light. I am surprized no one is jumping in here.

 

[tmgrash]

The pastel colors are nice but is this a symptom of too much. In all my research, I have never seen any warning of what to look for if you think you are supplying too much light. Yes, a quick change results in a rapid bleaching event but what about a slow change? Or is it even possible to provide too much light?

Anyone?

Example given:

Looks like too much light to quick to me. Back off the intensity for awhile and then slowly go back up. I run my AI's 100% for 3 1/2 hours a day so sps can take the light, just need to adjust more slowly.

 

[Felixc395]

90%?! Wow! That's a lot to me. These things are awesome. I have two sol blues over my 75 and run them at 40% for a couple hours at peak intensity! :lmao:

Those colors do look a little shocked. It wouldn't hurt to turn the intensity down just a little bit for a while or so. See how things do. Do you have/have access to a PAR meter?

 

[NatureNerd]

90%?! Wow! That's a lot to me. These things are awesome. I have two sol blues over my 75 and run them at 40% for a couple hours at peak intensity! :lmao:

Those colors do look a little shocked.

Thank you for your input, I will lower the power and see how things go. Note that "Shocked" would not be the right word. Nothing fast happened here. The lights were ramped up slowly over four months. The question asked was on total light level, not rate of increase.

I wish I had access to a par meter but, sadly, I do not. I run peak power for three hours. Peak levels are 90,80,80.

Other than the color of the example, the rate of growth of the shown colony is great. It more than doubled in size in 4 months. That, and my other colonies, look great. My Cal Tort, which is way up at the surface, has never had better color than right now, with deep blues. Just two corals are moving to this pastel look.

My question remains unanswered, what symptoms would one expect with too much light output? Let us assume acclimation to these higher levels was slow enough. Thank you for any input.

 

[NatureNerd]

just need to adjust more slowly.

Is four months too quick? This does not seem like I went too fast. That said, I will take your advice and back them down a bit. Thanks. The question remains, without a meter (and I am not sure I would trust getting accurate measurements anyway, relative maybe, but not absolute) how would one know they are providing too much light?

 

[Felixc395]

My question remains unanswered, what symptoms would one expect with too much light output? Let us assume acclimation to these higher levels was slow enough. Thank you for any input.

Fading in colors, bleaching, STN, polyp bail-out, death in extreme cases... Nothing good really. But for the most part you'll just see your cors fade and eventually bleach.

 

[birdman1979]

Garf bansai is a lower light sps. It loses it's coloration with too much par. Just what I have read though. I have no experience with this coral.

 

[NatureNerd]

Garf bansai is a lower light sps. It loses it's coloration with too much par. Just what I have read though. I have no experience with this coral.

Thanks birdman and felixc too. I have lowered peak power to the upper 60% levels and I'll give it a few weeks there and watch how the SPS's are doing. This may just be that with the switch to LED's, some of my corals are no longer in the best placement in my tank.

As I have said, most of my colonies never looked better. A bonsai, a tricolor, and to a lesser extent a ponape birdnest are just exhibiting this lightening. This got me wondering how I would even know if I had slowly ramped up too high.

 

[Felixc395]

It's obvious that you knew what you were doing going in with the lights, so that's a great thing. The specific pieces probably still need some more time or would like less light. You could lower them, or you could turn your lights down like you said you've done, but it's awesome to hear other pieces are flourishing! You could always frag a piece off a lightened colony and put it lower and see if the colors develop richer and come back darker as opposed to turning your lights down as well.

Best of luck!

 

[jc-reef]

This was taken from a post I made in the LPS forum and there may be more to it than just too much light. The needed 'spectrum' of light for those select corals may not be supplied from some LED's as it seems, especially the blue spectrum, the spectrum's peak is very narrow.....

Interesting. I was in Lake Mary this past weekend at the SRC bi-annual conference and one of the speakers (Anthony Calfo) touched on this exact topic with LED's. He mentioned that one of the issues with LED's is that the wave spectrum peaks are extremely 'spiked' at its particular Kelvin temp instead of a nice 'blunt' curved peak you get with a MH/T5 bulb. He said the range of Nm are very very small and specific with LED's.

His analogy was the LED's peak wave length is like a laser beam trying to hit its target (the zooanthella sp?) and if that 'beam' is not the exact color/temp needed for photosythesis of that particular cluster of zooanthella, then they are screwed. Most corals have several kinds of zooanthella in their skin and require different spectrum for photosythesis... i.e. 420-480. A blue LED may be more like 430-435 (example only)...causing the 'color shift' in your corals or even zooanthella die off (lightening).

It sounds like when you added the different color LED's to your mix, you 'widened' the usable spectrum peaks, thus allowing more zooanthella to photosythesis and keep their original color.

I wish I could find some true Spectrometer graphs that have tested (not marketed) some of the LED's out there.


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Taken from redfishsc post:

You can clearly see the 'narrow' peaks of blue.

http://www.reefcentral.com/forums/showthread.php?t=2017939

Here is the result of the LED testing we did about a week ago, along with a very good friend of mine who is a Marine Biology student at UNC Wilmington. Joe was fortunate enough to just get word that he's been hired by SeCore (yeah!) so these will be the only LEDs I'm able to study unless I happen upon another spectrometer.

The Spectrometer was an OceanOptics S2000.
http://www.oceanoptics.com/Products/s2000.asp

Current was held at 700mA with a benchtop powersupply for all LEDs except the XML graph below.

All LEDs were mounted to 1/2" thick acrylic (Corian) pieces as temporary "heatsinks", and held in place using jigs I constructed to keep things consistent.

For ALL test, the LEDs were 12" from the sensor. The sensor was never moved.

There are too many graphs to post them all here (28 graphs total) and about half of them are more for planted tank owners.

So I will link you to them in the following ways. Several people have offered to host them for us. Two of them are retailers so once they get them uploaded, I'll edit this post and include the link.

Here is my photobucket album with them all.
http://s919.photobucket.com/albums/ad39/re...TING/?start=all


Here are a few of the most important ones, but please by all means look at the rest of them. Some interesting stuff was found. Most of it predictable but nice to know for sure.

Y-Axis is not PAR but a unit of intensity that the meter assigns. We are looking for a way to convert this number into something useful, but it serves as a great comparison.

Rebel Neutral White and 2 Royal Blues

Rebel Neutral White, Royal Blue, Cyan

Cree XPG Neutral White, 2 XPE Royal Blue

XPG Neutral White, XPE Royal, XPE Blue ("cool blue")

XPG Neutral White, XPE Royal, Rebel Cyan

XPG Cool White and XPE Royal Blue

XML Cool White at various drive currents

A few others.

There are others on the album as well, including individual shots for the XPG cool, neutral, and warm white.... royal blue and blue, cyan rebel, XPE red and satistronics red, and various white-only combinations for planted tanks and refugia.

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[NatureNerd]

Most major LED suppliers have spectral curves for their LED's. These are accurate. It is not that hard to derive the spectral plot of a combined system like the AI Sol given the individual LED plots. I did this qualitatively before I spent my money. The graph was not that different than my MH. Remember that the "white" LED's are not that narrow spectrally.

The real trick here is to analyze what is needed for photosynthesis - What do the corals need.

 

[NatureNerd]

That last plot is pretty misleading. Here is what it looks like with appropriate spectral resolution.

There is a significant difference between the Cree XR-E blue and royal blue.

.

 

[jamgar]

I would really like to see some pictures of the coral after the lights have been turned down after a several weeks. I am going through the same thing.
Jim

 

[kevlow]

I hope that less intensity is the cure but I was also thinking along the spectrum lines. this is only based on personal experience and nothing more. When I changed the Led lighting to all RB and CW my Purples faded on both my LPS and acros. Growth and PE was great. Also my reds went orange. I have since mixed cree RB and CW and some ecoxotics including 403 violet. The purple in the LPS has returned but the acros improved but are still faded some.

Is the AI Sol heavy in the CW? Possibly backing down the CW and raising any violets or reds. I am not familiar with the AI. I do know this: Since changing my LED set up, the corals are growing more in the direction towards the 453 blues and not towards the more intense cree 3w CWs. This could be because they like the 453nm wave because this is the peak of photosynthesis; or , because of the less intense leds being used.

I will follow along because I am interested to see the results of your changes. I have been using LEDs for aprox 15 months now and am still trying to understand the changes i see.

kevin

 

[jamgar]

bump...any updates?

 

[NatureNerd]

bump...any updates?

Yes, I dropped peak values down to around the mid 60% level and the colors are deepening. It took a couple weeks to see a noticeable difference.

The corals that were doing extremely well at near 90% are still doing extremely well at the lower setting, and the ones that were getting that pastel look are starting to get darker more saturated colors. Like all things, it takes a while to dial it in.

Thanks for asking.

 

[chercm]

my Red also turned orange , i am using maxspect .

how to improve that one ?

I hope that less intensity is the cure but I was also thinking along the spectrum lines. this is only based on personal experience and nothing more. When I changed the Led lighting to all RB and CW my Purples faded on both my LPS and acros. Growth and PE was great. Also my reds went orange. I have since mixed cree RB and CW and some ecoxotics including 403 violet. The purple in the LPS has returned but the acros improved but are still faded some.

Is the AI Sol heavy in the CW? Possibly backing down the CW and raising any violets or reds. I am not familiar with the AI. I do know this: Since changing my LED set up, the corals are growing more in the direction towards the 453 blues and not towards the more intense cree 3w CWs. This could be because they like the 453nm wave because this is the peak of photosynthesis; or , because of the less intense leds being used.

I will follow along because I am interested to see the results of your changes. I have been using LEDs for aprox 15 months now and am still trying to understand the changes i see.

kevin