Effect of UV-A Spectrum on Acropora Growth and Coloration

[LeBon]

I rightly or wrongly assumed folk were slowly drifting back to mh and t5's (at least n hybrid form) because the corals were eventually losing 'je ne sais quoi' without the UV that the other bulbs provide.

 

[Dennis Cartier]

Based on how fast MH bulbs are becoming harder to source, I think LEDs will win the day (as expected).

That being said, there is still plenty of room for improvements in LED fixtures and spectrum. Tests like this help to see where improvements remain to be made.

 

[LeBon]

I presided over a non profit, growing plants for over a decade during the same sort of led bubble. We tested dozens but never changed from HPs's because altho the plants looked 'ok' the chemicals were not as broad. Perhaps that was a UV issue too. Why have full spectrum hps never been used on reefs?

 

[Dennis Cartier]

I presided over a non profit, growing plants for over a decade during the same sort of led bubble. We tested dozens but never changed from HPs's because altho the plants looked 'ok' the chemicals were not as broad. Perhaps that was a UV issue too. Why have full spectrum hps never been used on reefs?

I believe the spectrum HPS provides is too yellow for reef usage. Though the older MH bulbs that were 6500K, grew coral likes weeds. Not so much for the colours though.

 

[Jeeperz]

I presided over a non profit, growing plants for over a decade during the same sort of led bubble. We tested dozens but never changed from HPs's because altho the plants looked 'ok' the chemicals were not as broad. Perhaps that was a UV issue too. Why have full spectrum hps never been used on reefs?

UV a/b is known to promote increased trichrome production.

I love this experiment. Looking forward to the results as I use LEDs. If I can improve coral health with an additional light bar that I can repair at home when LEDs burn out that would be awesome

 

[J1a]

Sorry guys. The experiment got delayed.

The LFS is putting up an awesome 10ft display tank. So the place is undergoing a lot of changes.

Once those things are done. The experiment will resume. Meanwhile, the frags can heal and stablize, so once things are good to go, we can jump right in.

 

[J1a]

UV a/b is known to promote increased trichrome production.

I love this experiment. Looking forward to the results as I use LEDs. If I can improve coral health with an additional light bar that I can repair at home when LEDs burn out that would be awesome

Speaking of light bars, I have finally completed my light setup with the last addition of one more orphek OR3 today.

The new OR3 adds 365 and 740 nm to the existing 385 and 420nm.

With the 385nm addition, I have already seen impressive improvement to coral fluorescence.

These photo are taken with the light bar off.

 

[Superlightman]

Speaking of light bars, I have finally completed my light setup with the last addition of one more orphek OR3 today.

The new OR3 adds 365 and 740 nm to the existing 385 and 420nm.

With the 385nm addition, I have already seen impressive improvement to coral fluorescence.

These photo are taken with the light bar off.

I can not see the 365,380 on the spectrum from the bars on the webside?

 

[Nonya]

Effect of UV-A Spectrum on Acropora Growth and Coloration

Hypothesis:

1. UV-A supplementation can increase the growth in acropora sp.
2. UV-A supplementation can initate or increase the production of fluoroproteins in acropora sp.

Methodology :

Preparation :

1. Two fresh frags from a single acropora are made and fixed on frag tiles with scale.
2. The frags are labeled E (experimental) and C (control).
3. The frags are placed in the same aquarium, approx 6" apart. A black acrylic sheet is placed in-between them.
4. Using a spectrum photometer, measure the PAR and spectrum profile at both frags.
5. Adjust the position of the frags to achieve matching PAR and spectrum.
6. Culture the frag for one week to allow healing and observe encrustation.
7. Test and record water parameter.

Intervention:

1. Install a UV light strip (360nm, 380nm) over the experiment group.
2. Ramp up the intensity of the UV over 1 week, to approx 15% of the original PAR.

Measurements:

1. Diameter of encrusted base, weekly;
2. Height of frag, weekly;
3. Observable growth tips, weekly;
4. The coloration will be measured by taking photos of both frags using manual camera mode, with identical exporsure parameters, and edited using identical process (saved preset in Adobe Photoshop Express), weekly;

Maybe there is something, maybe there is not. We shall see.

I do not have space in my house to do this. Therefore I will be collaborating with a LFS here in Singapore to carry out this investigation. Let me know if you have any suggestions to improve this process.

Thank you for your time!

So is this supplementation or replacement?

 

[MnFish1]

So is this supplementation or replacement?

how is this an answerable quetion - its an experiment/

 

[MnFish1]

how is this an answerable quetion - its an experiment/

btw - -this was not a critique of what you said - I was just wondering - in probably more than a couple peoples minds - has already been answered?

 

[Nonya]

how is this an answerable quetion - its an experiment/

Easy. Is the experiment supplementing another spectrum, or is it replacing the spectrum with just UV? Easily answered, yes?

 

[J1a]

So is this supplementation or replacement?

It's a supplementation.

 

[Nonya]

It's a supplementation.

Thanks. What exactly are they supplementing?

 

[Nonya]

I do agree in having a control.

 

[J1a]

Thanks. What exactly are they supplementing?

Take a look at post #20, under the subsection under UV supplementation. It detailed the supplementation method, and light source used.

If you further read PAR matching, it detailed how we try to replace some of the regular spectrum with UV spectrum.

 

[o2manyfish]

When this gets picked back up, one thought for better measuring 'differences' amoung the frags is to weigh them.

Measuring a growth ring may not give a full picture as to how much the coral is growing in relation to the available light. Not only will a coral encrust but it's going to grow in other directions as well. And the only way to measure this from coral to coral is to track the mass of the coral frag itself and then chart the changes in weight in all the different test groups. This will also make it easier to see the effect(s) using different types of coral in the experiment.

You might find that red/yellow corals are going to have a bigger influence than a blue/purple.

Dave B

 

[maxwell]

Having tried 7 different reef bars im interested in ur findings as all the reef bars ive tried had 90 degree lenses and 36 leds the OR3 blue plus at approx 16'' off the ground gave a hot 6'' to 8'' wide hot spot of light with a par of around 200 and at the edges of the hot spot it had approx 60 par reduction which to me limited the benefits of such bars . I have taken of a reefbrite xho and 1 x OR3 Blue plus and a OR3violet /actinic and now testing 2 quantra meso bars because of the spread due to wider lenses and increased par to see if i get better coloration and growth. pics are OR3 Blue plus and Quanta meso blue

 

[J1a]

Sorry everyone for the delay. The lfs helping me out is doing a major upgrade. This will resume after all those electrical upgrades are done.

@maxwell , I am afraid the experiment won't address the issue of spread though. We are basically adjusting for a point measurement.

 

[Nonya]

What's the sensor?