Anyone growing German Blue Digi under LED?

[mcarroll]

I'd love to see some before and after pics of German Blue digi. under your old lights as well as under your LEDs!



I've never seen that coral have great color under anything but metal halide, though I'm sure it's possible under the right T5 combo too.

Curious what results people are getting under LED's with this coral. The one attempt I've seen is very beige.

Thanks!

-Matt

[Shard]

I had some that came from a tank covered by LEDs. I have it in a NC 28 with a 150w MH HQI bulb and some PC actinics. I think it has colored up a bit more under the MH.
The flipside to this is I have a purple grape monti that came in with the same batch, and now looks less colorful under the MH.

I will be moving some back to being underneath LED, so I will try and update this thread down the road.

Why the particular interest?

Landon

[mcarroll]

That coral is a "canary in the coalmine" for color in a way. Mostly because I love the color of it when it does look its best -- that kind of blue is so hard to come by, and it's such an easy coral -- so (under my 160w 20K Radiums) I have it growing just about everywhere I have room for it.

The MH replacement schedule (every 5 months - or else!) has got me seriously considering a set of Aqua Illuminations Sol Blue fixtures. They'd be paid for in something like 5 bulb replacements, not counting power savings. I'm just not comfortable upsetting a system that's going so well and looking so good for what may be sub par results in one crucial way. (Note, there's no question in my mind that corals will grow - and fast - under LED.)

...and there just aren't enough people posting results shots of their LED-grown corals - especially the before and after shots. Tons of hoopla and build threads. (Tons!!) Not so much documentation of the results.

-Matt

[Shard]

Sub par results how? Coral color?
I really would not be that worried about it. I have read so many threads of people talking about how "something has to be missing" and they want to see proof of coral growth before they switch to LED. Like they need to see that coral grows, in salt water, with LEDs before they will believe it. The scientific proof is there, what more do you need. The PAR output is incredible, and the spectral analysis is close to that of MH, and covers the whole visible light spectrum very well, with peaks in the proper places.

If something is missing, tell me what it is? I have yet to see any valid argument for this belief, but would surely like to hear one if it is out there. I have come across the one about UV, but will debunk that one a bit here....

I have heard some say the color fades because LEDs do not emit UV, but MH bulbs do. I am a grad student in Biology, so believe me, I have read my fair share of papers covering photosynthesis topics and corals. Part of the argument is that coral color is the result of 'sunscreen' compounds generated in response to UV. I have yet to see any convincing evidence that coral colors are the result of UV radiation. It is often repeated in popular literature, but I haven't seen a scientific study reference yet that shows this is the case. If anyone reading this has seen such a study, please let provide me with a citation or link, otherwise I am going to continue to assume it is a just an assumption.

This is also irrelevant and most likely not true because the glass covers used on the lights should filter out all, if not most UV emitted by the MH bulbs. There is little UV present, if any, in the captive environment anyway. Regardless of light source. So scratch that argument.

Thinking of UV and corals... there is one study I have seen related to this topic. In the study researchers showed that man made UV compounds in sunscreen can cause corals to bleach and die due to inducing the lytic viral cycle in latent viral infections when present in low concentrations in the sea water. Anyway.. back to the topic of corals and LED....

Thinking of Chlorophyll...
There is a newly discovered type of chorophyll, labelled Chlorophyll F, which absorbs light in the IR spectrum, peaking at about 706nm, but I am not sure this relevant to corals, because I have not read anything showing that it is present in zooxanthellae. I have also not seen any spectral pattern charts comparing lighting options in this range for reef tanks. There are several different types of chlorophyll with different absorption spectrums, and not all are present in every species that is photosynthetic.

I really think most of the fading seen by new adopters is the result of a massive increase in intensity from their previous lighting setup. If I were you, I would install the LEDs, but would take some PAR measurements before you remove the MH fixtures, and adjust the settings so that your PAR output from the LED fixtures matches that of your MH setup. Then slowly ramp up the intensity after that, or just leave it set where it is.

I have had my AI fixtures up for a few months now. My colors on my LPS look exactly the same, because I have the whites only at 40%. I don't have much SPS in that tank, but I do have a few. I would say my huge montipora colony looks better now under the LEDs than it ever did under the MH setup. Growth was amazing with it also.

Personally, I think Plasma lighting may be the future. Replacement cost per bulb is low, and they last tens of thousands of hours also. They are also a little more efficient, putting out more light at lower power than even LEDs I think. They are already proven in greenhouse setups, and have been used for plant growth setups for a little while now with great success. The color spectrum of them is not what we are looking for, but they have been playing with gas mixtures to change that and have already been able to shift from 5300k to 9000k at full power if I recall correctly. The LIFI plasma lights also shift color as you decrease intensity, so you can lower the intensity to get a dimmer effect, or shift the color more towards 20k.

Hope all this helps, and good luck,
Landon

[tkeracer619]

I think you missed the point of his question.

He is asking about a particular coral that is very hard to get to color up.

He has it all over his tank and it is doing well. We are talking about a coral that many people try over and over to get thriving only to fail.

To the OP. It is a brilliant coral. I know your lighting schedule sucks but if its working well for the coral and you have a lot of it I wouldn't change a thing.

[Shard]

I think I got the point of his question. The question seems to be is there an issue with coral coloration under LED. I was trying to get the point across that there is no data so far that shows anything is missing from LED that is there with MH/T5/etc. If the OP intended for another interpretation of his question, my apologies.

I did post earlier about my results with blue digi, under both LED and MH, but I have not really done a whole lot of analysis of it's growth. I will make frags from my colony and place one of each under both lighting arrangements to see what the results are. If I could get a par meter I would place them in a location under each of matching intensity to try and normalize the results a bit.

I agree with you that if things are working, it is best not to change it, but I think the cost of constant changes are starting to add up for the OP. Gosh I would hate having to change out multiple bulbs every 5 months!

Hope this helps,
Landon