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DIY Lighting - Wattage Input or Output Used?

Jimbo1981

Seedling
Joined
21 Mar 2017
Messages
24
Location
London
Hi All,

I'm a bit of a newbie to the planted aquarium scene, I've recently read numerous articles and watched many YouTube videos on lighting as i am intending to create something myself with either CFL or LED (6500k).

When it comes to Watts per Gallon/Litre it seems common that a Medium to High lit tank should be in the region of 2-4 Watts per gallon (according to my research, please correct me if this is wrong). However, no one has stated whether this is the input/usage value of the light or the output value of the light.

I have a 30 (ish) gallon (140 litres) tank and was looking at lighting it with 2 x 30W LED flood lights, totalling 60 Watts (@ 2 Watts/Gallon). However, the LED's state they are the equivalent output of 100W each... So would this therefore be miles to much light? I have uploaded an image of the sort of lights i was looking at...

dc653c0959572722.jpg


The 30W LED floodlights i saw in one video, looked to be giving out enough light and can only presume this was the usage/input value that he gave.

Any advice from some lighting gurus would be much appreciated


Thanks

James
 
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I have a 30 (ish) gallon (140 litres) tank and was looking at lighting it with 2 x 30W LED flood lights, totalling 60 Watts (@ 2 Watts/Gallon). However, the LED's state they are the equivalent output of 100W each... So would this therefore be miles to much light?
Yup. The Watt per gallon/litres reference rule is not applicable to LEDs, as they are way more energy efficient than other types of bulbs when talking about the amount of light per Watt.

With LEDs people usually look for info on Lumens, PAR, or PAX measurements to get an idea on how much light you are getting.
 
Hi Kadoxu

Thanks for your reply. Do you know how many lumens i should be aiming for with a Medium to High lit tank? Is there a similar Lumens/Gallon ratio as there is Watts/Gallon?

Thanks
 
I don't really look at lumens myself, since it only measures the amount of light perceptible by the human eye, and plants tend to use a wider range of light frequencies that we can't actually see, but people who do say that the absolute maximum amount of lumens in a tank should be 6000.

I always go for PAR (Photosynthetically Active Radiation) measurements, which sometimes are quite difficult or even impossible to find unless you have a PAR meter lying around. There is a thread about PAR measurements on a few LED light fixtures going on here in the forum:
https://www.ukaps.org/forum/threads...ihiros-led-par-data-the-power-of-light.43178/

Low light - 15-30 PAR
Medium light - 30-50 PAR
High light - >50 PAR
 
Hi Kadoxu

That's interesting to know. I have gone and ordered the lights shown in the above image and will run a test as they were only £15 for two on eBay. I actually have a Seneye device, which is able to measure PAR so i will see what the lights output and will compare them against your data figures. Will be the first time i've used that feature on the Seneye. If it turns out they Floodlights are not suitable i'll do a bit more research and try something else.

According to the data on the floodlights the Lumens should/could be in the region of 4000 :bookworm:,:facepalm: lol. They also did 10w versions in a pack of 4, so that might be another option if it's just a case that they're to bright.

Thanks
 
Is that the Seneye reef par meter? I've got that and would be curious if others had tried it.

Bit late but any LED I buy now is dimmable. Just gives more control for my tank.


Sent from my iPhone using Tapatalk
 
Been following a number of videos on YT and it's a bit off putting to see that the lights you get from eBay sellers vary so much.

Some of the 10w tested were actually being rated by the testers as a little over 3w. Still I guess it's the same with everything on eBay, you buy and if it's not what it's supposed to be you either return it or don't but from that seller again.
 
Hi Delapool, yes it's the Reef version. I mainly used it for checking toxic levels in the water in my first tank. I've never needed the other features until now. I do wish i had gone for dimmable Light as you suggest, but these Floodlights were cheap enough that i can change later. I just fancied experimenting a bit, rather than paying £200 plus per light ("cough couch" Kessil...) from the outset.

I watched a few of those too BarryH, and it appears that they're putting lower wattage drivers in them. I did email the seller asking to confirm they were 30W's (referring to those test videos) which they did confirm... Although that was before i asked the forum about output/input wattage i needed... So it would probably do me a favour if they weren't as powerful as they state haha.
 
Hi Kadoxu

That's interesting to know. I have gone and ordered the lights shown in the above image and will run a test as they were only £15 for two on eBay. I actually have a Seneye device, which is able to measure PAR so i will see what the lights output and will compare them against your data figures. Will be the first time i've used that feature on the Seneye. If it turns out they Floodlights are not suitable i'll do a bit more research and try something else.

According to the data on the floodlights the Lumens should/could be in the region of 4000 :bookworm:,:facepalm: lol. They also did 10w versions in a pack of 4, so that might be another option if it's just a case that they're to bright.

Thanks
I also have a Seneye and it's usually what is used around here for PAR measurements. Make sure you measure at 2 or 3 different heights (water top, mid tank and substrate level) and 2 or 3 different areas (center, near front glass, near side glass) on each of them as well to get an idea about light dispersion. The sensor should always face the center of the light (i.e. when measuring near the front glass, you should tilt the seneye a bit to point the sensor to the light).
 
Thanks for the tip Kadoxu. Does it have to be done with the tank filled with water, or can you do it with an empty tank?
 
Keep in mind the refraction of light in water, as it increases light dispersion.

With water in, if you want more realistic measurements.
With no water in, PAR readings will be a bit higher on deeper levels.
 
I do wish i had gone for dimmable Light as you suggest, but these Floodlights were cheap enough that i can change later.

Still you could use these cheap flood lights housing and upgrade them.. :) Ive been ordering and testing these COB units and how dimmable these are.
https://nl.aliexpress.com/item/Dura...m-12V-White/32769942273.html?isOrigTitle=true

http://www.banggood.com/DC12V-12W-Ultra-Bright-COB-DIY-LED-Lighting-Lamp-Bead-Chip-p-1078891.html

And these run on regular 12 volt powersupply as long as the watts are met. No need for a constant current. These run on a car battery if needed..

Are dimmable with a very cheap and simple PWM controller. Like this bellow Pulse Width motor controller.
http://www.banggood.com/2Pcs-Adjust...Controller-Switch-p-944199.html?rmmds=myorder
These controller do not go all the way to 0 with their output, via potentiometer from 5% to 100%, so a timer switch is required anyway if you want no light at all.

If the flood light housing is metal and big enough to snugly fit one of these, it will function as cooling as well.. The PWM controller migh be small enough to fit next to it and just need to drill a hole to fix the potentiometer. Or put it in the cabinet next to the power supply. If the housing of where you build it in doesn't have proper cooling properties. Than you might need one of these as well..
http://www.ebay.com/itm/DIY-100mm-Aluminum-Radiator-Cooler-Heatsink-Chip-for-LED-IC-Power-Transistors/272438576075?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=2&asc=20131003132420&meid=3c8ab53f8ff345e694af60f9fe2dfc0a&pid=100005&rk=3&rkt=6&sd=282297472392
And a tube of thermal greasy of course.. :)

Anyhow as you can see, it aint all that expensive if you can handle a drill and a soldering iron and keep cable colors apart. Just need to find a housing it fits in or make one.

Here is a little vid of how i dimmed it with above parts. Used an old desktops ATX PSU providing the 12 volt and a PWM moter controller.


:thumbup: Don't know any of your skills, but for those bold enough, just to give an idea.
 
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Well the lights turned up today, so quickly tapped them to a bar, wired them up (temporary) and they actually look about right (from eye). Obviously i'll do all the PAR and lumens checks shortly and update you, but so far, so good. By eye, they're looking almost as bright as the lights in the stunning ADA Gallery.

IMG_2318.JPG


The housings are very slim, so unlikely i'll be able to modify these ones Zozo. Like to think i'm pretty good at the ol' DIY stuff so giving it ago shouldn't be a problem (just built a Star Wars bunk bed and pretty sweet playhouse for the kids lol). It always just comes down to whether it's cost effective, else might as well just go for something pre-made and spend the cash - that's never as fun though :)

Anyone else looking at getting these in the future, then it's Worth noting that I did actually open them up and checked the wiring etc and the quality all looks fine... So for £15 for two, i'll be well happy if they do the job. I'll submit a photo of the lighting rig once it's all done and let you know the data shortly for some feedback
 
Looking good Jimbo. It would be good to see a photo of the lights temporarily in place over the tank.
 
Here you go BarryH, although they look better when held above the tank, but I need another pair of hands to get a photo of that. Give's you an idea though...

IMG_2320a.jpg


FYI The tank isn't staying on the desk, I need to build a new bigger cabinet for this tank first. Then i can mount the final lighting solution from the ceiling... So this will be about as far as i can get this week.
 
Thanks Jimbo, very nice.

The LEDs are much thinner than I had expected. They normally have a large box on top of the heatsink.
 
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They look realy nice Jimbo.. :) I've seen them before, but not in real life.. If you open them op you'll find a PCB where the leds are soldered to.. These also contain the driver, which is likely a 6 or 8 legged chip.. In many cases this chip also contains a DIM pin, depending on the chip used it probably still can dim in various ways.. If for example the PCB contains the PT4115 chip it has a dim function which will not be connected in a setup like this. Many other driver chips used have simular function.

But in case just hope it is the PT4115.. Depending on the type it has a dim port on pin 3 or 8.. Then you would need to put a 0 to 5 volt pwm signal on that port and they dim like a charm.. 0 volt is full power 5 volt pwm is 100% dim.. So every 1 volt difference will be about 20% dim.

Just find out which driver chip is used and find it's data sheet. :thumbup: You might have some hidden not connected functions in it.. ;)
 
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I know you've bought your light Jim but I've just found these 15w Benchmark ones.

British company and very stylish. As my lights didn't turn up yesterday as promised, I looked on the suppliers Facebook page to see if anyone else had been having problems and found a link to the supplier of the Benchmark 15w floodlights. Loads of other interesting lighting on there as well. The video is for Warm White but they have Cool White too.

 
They look realy nice Jimbo.. :) I've seen them before, but not in real life.. If you open them op you'll find a PCB where the leds are soldered to.. These also contain the driver, which is likely a 6 or 8 legged chip.. In many cases this chip also contains a DIM pin, depending on the chip used it probably still can dim in various ways.. If for example the PCB contains the PT4115 chip it has a dim function which will not be connected in a setup like this. Many other driver chips used have simular function.

But in case just hope it is the PT4115.. Depending on the type it has a dim port on pin 3 or 8.. Then you would need to put a 0 to 5 volt pwm signal on that port and they dim like a charm.. 0 volt is full power 5 volt pwm is 100% dim.. So every 1 volt difference will be about 20% dim.

Just find out which driver chip is used and find it's data sheet. :thumbup: You might have some hidden not connected functions in it.. ;)

Thanks for that info, i'll probably do some reading first as that's just gone "woooosh" over my head with the electronics side lol.
 
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