# Inexpensive COB LED



## Aqua sobriquet (31 May 2019)

I’ve yet to get a proper light fitting but I’ve just jury rigged something to see what it looks like. A is an Eheim 7W COB LED and B is a cheap 12W 6000K COB lamp from China. The 12W is not surprisingly brighter but the colour doesn’t look much different to the Eheim. What do you think?


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## Siege (31 May 2019)

Both nice. I think the Eheim if you can lower the height to make it a tad brighter? B may be too bright.....?

One comment. 
Can you slide a gravel flattener or old club card down the front of the substrate to push the sand down? It’ll look a lot better if you can’t see the plant substrate.


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## Aqua sobriquet (31 May 2019)

I’m planning on keeping the Eheim on the 10L Nano in the picture, it’s at its lowest height. The 12W lamp will be used on a 35L Nano.

It’s just a truck of the lighting, there is no substrate it’s all sand!


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## zozo (4 Jun 2019)

Those china cob leds are OK.. Tho they take us a bit for a ride when it comes to output performance it aint always true to what the seller presents.

I'm using them for quite a while now and have no complains.. I like to use the MR16 12/24 volt dimmable versions. They are easily controllable with a simmular cheap dimmer, such as a $4 PWM motor controller.

But to give an example i bought a 12 watt cob led stating 1000 lumen.. I screwed it open to look what's inside. The cob led unit in it was a 7C2B 24 volt 300mA 700 lumen at 7 watt. 
https://www.tmart.com/XC-7C2B-7W-21-25-2V-630-700LM-White-Light-COB-Lamp-Bead_p224141.html

Conclusion: How the hell do they get 1000 lumen out of that?.. They don't.. They also do not tell you if you run it on 12 volt it likely gives you even less because you run it dimmed at 12 volt. But if you are planning to dim it anyway and it's enough light. Than it doesn't realy matter. And it only  consumes 7 watt instead maybe even less at 12 volt.

Just beware the specs of what they give are in most cases strictly commercial.. Since the majority of the buyers can't check on it's true performance anyway and has to take their word for it. I also didn't check with a flux meter etc. Just found a 7 watt unit in an alledged 12 watt.


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## Aqua sobriquet (4 Jun 2019)

They didn’t actually quote a lumen output for the lamp I bought. It’s clearly brighter than the the lower wattage lamp I have though so that’s ok. I’m thinking I should maybe have spent the extra 50p though and got the dimmable version as it may be a little too bright. I may be able to get away with it though by raising it a little higher over the tank. For £3.28 though I’m well pleased if it lasts ok.


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## gregl (3 Aug 2019)

How did you make this mate? And what is the stand for the light?


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## Aqua sobriquet (3 Aug 2019)

I bought the 12W COB LED from Ranpo Lighting on eBay.

There is a wide choice of fittings but I chose the E14 or small Edison screw. I also bought a ceramic E14 lamp holder and fitted it inside a piece of aluminium tube for a housing. It’s wired up with green cloth covered 3 core mains flex. The stand itself looks like a laboratory retort stand but I actually made the base from some heavy steel plate some years ago. The column was just a piece of 13mm aluminium rod but I beefed it up a bit by screwing it into a short length of 20mm stainless steel rod. I already had a couple of bosses and a clamp but I bought a new nicer looking clamp. I made some cable clips as well but you could just use cable ties. This is how it is at the moment.





This is an old original retort stand I’ve had for some years together with a boss and a clamp. You can get these on eBay amongst other places. The bases vary quite a lot and some are just a simple metal plate.


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## gregl (3 Aug 2019)

Brilliant! Never thought of using a retort stand. Cheers for typing that up mate.


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## Aqua sobriquet (3 Aug 2019)

No problem hope it helps. This is the LED I bought, not bad at all for £3.28.

https://www.ebay.co.uk/itm/LED-Dimm...-12W-220V-RT729/233172743336?var=532655841987

There are other vendors with lamps up to 15W. I wouldn’t be surprised to see 20W versions at some point.


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## Aqua sobriquet (21 Dec 2019)

Just a quick update, I’ve been running this lamp for several months now and the plants are doing really well. In fact I’m having to give them regular trims. Admittedly I only chose easy to grow plants, mainly Anubias and Moss. I’m really glad I tried this lamp though as I could so easily have spent hundreds on specialist aquarium lighting.


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