Just Been Given £1500 Worth Of Led Lighting

As the title

A friend who is an electrician gave me 2 x 7 foot 24v led lights yesterday and a driver that can power 3 of them, hes hoping to get me the third next week!

These where feature lights from an Airport they are IP67 rated and are the nuts! they where only fitted for a week then taken down and have sat in a cupboard, I opened them up last night and cut a foot off so they fit above my 6ft tank, they are in sections so it was just a case of opening the tubing they are in and then inside they are mounted to an aluminium rail and just cutting the required amount off, there is a dimmer fitted to the driver as well and they are so bright its unreal! far better than my current 6ft T8's

Im am chuffed to bits as they really are expensive lights and look great, the shimmer is fantastic and its not often you get something for nothing these days!!

photos photos

will do at the weekend!

A light emitting diode emits its light at a particular frequency, not in a broad spectrum as we are accustomed to having. Do you know what wavelength/frequency the light emits? It is probably a great light for viewing your fish but may or may not be any good at all for any plants that you want to grow. It sounds like a nice pickup for plain old viewing lighting though. For plants, you need to go toward the red ad blue ends of the visible spectrum and don't really get much use from the center of the band. For our eyes, the center of the band is where we get the most perceived light for a given light intensity.

Thats fine on the plant side, my Jaguar and plants don't get along! ive tried plants before they last about 2 hours!!

I have the spec of the lights from the manufactures site, just trying to find an English copy that makes sense!!

thedc5 said:

Thats fine on the plant side, my Jaguar and plants don't get along! ive tried plants before they last about 2 hours!!

I have the spec of the lights from the manufactures site, just trying to find an English copy that makes sense!!

Click to expand...

Yep, where's the pics!!!

You may never suffer any algae issues then either I guess...?

OM47, does algae have the same requirements for the light spectrum as plants?

I only ask because I am toying with the idea of no plants in my new tank when it arrives, just bogwood and lots of rock...but am concerned about algae blooms without any plants to gobble up anything that algae will need to flourish...

Can you tell I still have a lot to lean about plants and algae

Algae is a plant. When you have terrible light in terms of plants, you have a light that will not grow algae either. I would guess that you would find it worthwhile to discover the actual frequency / wavelength of the LED fixture you are using.

right managed to find the what I think is the spec of them, see below robbed from there website! I have 2 of these although I did cut a foot of each as they where 7 foot.

Forgot to mention these are currently sat on top of my tank using the mounting clips upside down they act as feet but I will hang them I think in the end just to get them out the way.

Cant get photos till I find the charger for my camera! no doubt buried in a cupboard somewhere will upload them as soon as I can, for now here is a uninspiring picture from there website!


LED


Spec:
Tubular luminaire, resistant to pressurised water, made of PMMA transopal with anodised internal aluminium reflector.
IP 68, 20 m, protection class II.
End caps with quick-release fasteners flush with polymer tube.
With 48 Power-LED, power input 57,6 W, white 854/5400 K, approx. 40 lm/Watt. Supply voltage 24 V DC.
Electronic transformer for max. 20 / 100 / 200 W, in separate polymer housing IP 65,
supply voltage 24 V DC, primary voltage 230 / 240 V, 0/50/60 Hz. To be ordered separately.
Mounting with polymer and stainless steel mounting clamps.

The 5400K means the light range would be good for plants but it does not come back to the specific frequency. The problem that I am having deciding is simple. A spectrum is rated based on what the typical wavelength of the source would be compared to a hot wire, in this case at 5400K. That light can be composed of a single wavelength, which would be totally useless for growing plants, or it could be composed of several different wavelengths that balance out to give the same overall color impression. Plants do not use the green part of the spectrum, which is why they reflect green and we see that as their color. Instead, they use light from the blue and the red ends of the spectrum ,which is why specialty growth lights seem a light purple to our eyes. I suspect that spectral information on your LEDs may be hard to come by from the vendors. They are likely aware of it but not inclined to advertise it because it would be so much gibberish to many people. Spectra are usually shown graphically with wavelength plotted against intensity.

I love talking to people who actually now about this stuff!! having always kept large Cichlids I have never looked into plants at all!!

I have found a pdf with a graph on would this be what your talking about?? (screen shot attached)

I usually don't see such a plot on polar coordinates but that is OK, I can read a graph even when it is presented in a less useful fashion. If you laid that out on a typical x-y coordinate system, it would show a rather low value most of the way across with a large peak around the central frequency. That is showing a central peak with a rapid drop off to each side of the central frequency which is much like we suspected with an LED. What it means to you is that the light is in a narrow frequency band and I am not seeing anything that makes sense to me in the coordinate system that tells me where that peak is except in the stated spectrum of 5400K. What it is saying is that the light really is composed almost completely of light that is the color you see when you look at it. If you used a prism to split some of the light into a rainbow, you would only see one color stripe, not a rainbow.

well they are not aquarium lights as I said they are sold as white lights for feature lighting, they look great in the tank and they produce very little heat, I guess if you have plants they are a no go but thats fine for me right now!

Thanks for the help anyway! its always good to find out a bit more about anything really!!

You might actually benefit in some way, if algae has all the same requirements for light as other normal plants then having such a narrow band of light would not make it easy to grow either, you may get away with more "on" time

Either way its much nicer looking than the T8's I have and it was free so its a bonus however I look at it!