Led Lighting and the reef tank, an old myth

Andre@ReefAquatics

Andre@ReefAquatics

Joined
18 Dec 2012
Posts
2,722
Reaction score
169
Location
Durbanville
Led Lighting and the Reef Tank, does not work, now just an old myth ??

Opening up a kinda quiet but much debated topic about Led Reef Lighting and the reef tank.

I'll start off the controversial topic.

We know that you get cheap China led units and you get American brands that cost four fold.

I visited home reefs on a daily basis and my overall conclusion is that it boils down to the reefers husbandry. I now can conclude that I've seen reefs on led lighting I've not seen or heard of before but their thanks are absolutely awesome.

I've visited reefs with R45K lighting over their reef and it looks like sh*t.

The TOM a few weeks ago was born with so called entry level lighting, an absolutely stunning tank ???

I leave this floor open for technical discussion.
 
Last edited:
My opinion was always thats its the reefers that under bought due to initial cost outlay and then blamed led lighting on the whole.

And boldly I also blame the naughty lfs for under quoting and selling rather one unit than 2, double the cost who turn the potential sale away, if you quote 2 you run the risk of selling no led so you rather let the reefer leave with one unit. Sale done. The result is the end user ditches led cos its crap and the word spreads.
 
Last edited:
Andre@ReefAquatics said:
Opening up a kinda quiet but much debated topic about Led Reef Lighting and the reef tank.

I'll start off the controversial topic.

We know that you get cheap China led units and you get American brands that cost four fold.

I visited home reefs on a daily basis and my overall conclusion is that it boils down to the reefers husbandry. I now can conclude that I've seen reefs on led lighting I've not seen or heard of before but their thanks are absolutely awesome.

I've visited reefs with R45K lighting over their reef and it looks like sh*t.

The TOM a few weeks ago was born with so called entry level lighting, an absolutely stunning tank ???

I leave this floor open for technical discussion.
Click to expand...

Correct me if I am wrong,through the research I have done on lighting, the main factor is to get the correct intensity lamp, then the correct height from the livestock for the intensity of the light, and then to choose the lamp with the required wavelengths for the livestock that you will be stocking.
So my actual question is: why does it matter where you purchase the lights from.
Or is the debate specifically about undercutting importers of well known brands.

The quote above shares my sentiments.
every reef keeper is responsible for his/her own tank, and should research the required parameters for each individual in the environment to make sure that all livestock are compatible. that's just my 5c
 
another thing to consider is LED is basically laser light, light generated not from heat but from a diode that emits light and not heat, are corals supposed to grow under such light?

The sun burns gas and light is generated from heat.
MH lights produce light from heat and a chemical reaction.

LED's get hot but the light emitted is it from Heat or from actual diodes producing light?

Do corals mind what type of light they get based on what they are used to from the sun?
 
My corals seem to grow good under LED's. However, i have only ever used LED's so it will be impossible to say whether corals grow better under led's, t5's or MH's.
That said, my corals grow very well, and i will have to upgrade pretty soon. Luckily that is in the process.
So i agree with Andre, it is a combination of many different elements, lighting(spectrum, intensity etc.), correct maintained parameters, removal of detritus build up, cleaning filter socks-sumps etc religiously.
There are very many factors that go into having a successful reef tank, not just lighting. As said, you can have the fanciest equipment available, pay little time and attention to your eco system in a box and you will not get results.
 
I bought the cheap Chinese Beamswork LED's off ebay, the 3w ones, started my nano on them and the SPS grew fine, the monti's were plating nicely, all of the sps frags had multiple white growth tips on them, no issues whatsoever, the only reason I upgraded to a Pharos LED was for the fancy moonlight cycles and automatic sunrise and sunset. Apart from that, the much cheaper Beamswork lights were 100% fine. They were only blue and white too, none of the UV and yellow and red etc. Corals grew fine, I was getting really good growth. So yeah, not all "cheap Chinese" lights are bad.
 
I think the biggest problem with LED units is the directional light. T5 and MH is all over the place and the reflector helps in bouncing light towards the tank, but not from a single point.

On a 1.2m tank, having 2 units that both can cover 600 by 600mm. What will you have? 2 spots directly under the lights that is fully saturated from above. Any opening coral like acropora or pincushion will get all the light from directly one point above them. Shading the rest of the rock as they grow. The stem part of the acropora will be in its own shade.

Under T5 at least the length of the tank would have been in the "spotlight". But with 2 LED units, it's like your car lights close to the garage door. 2 bright spots directly in front of the lights, but dark in the middle.

I reckon that even if a unit can cover 600 by 600. You need to use 3 on a 1.2m tank. To light up the middle and to provide overlap for the other 2. Same if your car get a center light.
 
RiaanP said:
I think the biggest problem with LED units is the directional light.
Click to expand...

I think you bring a very interesting point to the table, some even struggle with shadow and reflection on T5 and MH, if we think of light via the source of the sun, there is no specific point the light comes from in terms of a single point, the sun comes up and throws light, even tho it may be not as intense in the morning as it is at noon, to correctly setup an LED light system the LED's, I believe need to be placed in a arc like fashion over the top of the tank creating better angles and less shadows:

https://encrypted-tbn3.gstatic.com/...CBz_lBgqYDOXZAh3Tmy2diOiIgHNDMQ8J7d1_enrLcEDA

Not only left to right but front to back too.
 
Put it into a picture.

This is not my best effort, as I'm only trying to illustrate my point. With 60 degree optics. Keep in mind that leds provide most light directly under it. The edges is not that bright.

On the left, 2 light units. The white thing is supposed to be a coral. It is on top of an imaginary rock stack. It get light directly from above. its base is in darkness.



In the middle, another light unit is added. The same coral now receives light from the side. Still all the light from above with a bit from the left.

On the right another unit is added. Same coral is now almost in line for 2 units. If the coral base needs light moving it slightly to the left and it will have light from above and from both sides.

So even if the LED unit can do 600 by 600mm. I reckon you need to space them closer together to get a lot of overlap.
 
i don't think a tank with LED struggles with the above if the entire tank is covered via an LED unit that is made for a specific length or tank, however a single unit with in-line LED's would struggle with shadow lighting from front to back unless a few more units are added, so same priciple as your pictures but from front to back. Also remember you are not limited to a 60 degree output, I have bought 90 degree lenses as well, if you leave the lens off, you get 160 to 170 degrees worth of output.

What would then cure that solution is have a staggered LED outlay with variable lenses or with different lenses.
 
My view is as follows: LEDs came into the market to solve two issues, lamp replacement costs and energy saving. So using LEDs was going to save you money but not having to replace your T5 or MH lamps every 6-12 months, but now you can get 12-18 months on T5 and MH max 9-12 months, but you incur a far greater purchase cost upfront instead. As for point 2 in the beginning you saved power replacing 250W MH with 170W led units but now not so much with 5W, 10W and even 100W led chips.

But I agree I have seen tanks with just LEDs that look dull and seen MH and T5 tanks too, while light is important it's one link in the chain
 
You must log in or register to reply here.
Back
Top Bottom