Quick review of ebay LED strip

[hotdrop]

Why not? Couldn’t you just change the resistor on the pwm circuit to provide a higher voltage across the series. It’s not a good design but it will Work until you get thermal runaway

 

[oreo54]

Why not? Couldn’t you just change the resistor on the pwm circuit to provide a higher voltage across the series. It’s not a good design but it will Work until you get thermal runaway

Huh???
PWM is on/off for one thing if referrring to the control circuit.
As to the PWM output:
Driver keeps current constant so adding a resistor doesn't seem any different than adding another diode.. both will do nothing to change the current at the other diodes..
AFAICT.. though this goes beyond my basic understanding of it..

A LED driven with a constant current will dissipate I*Vf Watts. If it has a resistor in series with it, the LED dissipation will be I*Vf, but the resistor wastes an additional I*Vr Watts, where Vf is the forward LED voltage and Vr is the resistor voltage. Just wasted power in the resistor because it can have no influence on the LED power...

https://forum.allaboutcircuits.com/register?next=registertoview

 

[hotdrop]

Well heating up a resistor is one way to cheat and reuse the same circuit but you can just overspec your smaller strips. A constant current driver doesn’t care if you are driving 1 led or 10 it will vary voltage to match resistance. Check out the specs on LDD 350 for example. The only problem with over speccing is you loose efficiency as you get further away from full capacity.

 

[Jerzyray]

Was hunting around ebay for light strips, and found:
54w/81w/108w PopularGrow Blue White LED Aquarium Light Bar Fish Tank Plant Coral
sold by ledlightplant

So here is a quick review:

I picked up 2 of the 81w version. It's just shy of 3ft long. It arrived quickly via DHL, (less than a week), and was packaged super well. No damage at all. Comes with a few small swivel brackets for mounting to a wall or canopy, and two tiny eye bolts. There are 4 captive nuts in basically a T slot that slide around freely, so you can position the brackets wherever you want, or remove them and use the little eye bolts for wire hanging.

They claim it's waterproof. Didn't actually test it, but the quality looks good. All the seals look correct, the little power supply has one of those watertight screw connectors with an o-ring.

Comes with a simple instruction page printed in english and german. Instructions were readable and generally useful, but the whole thing is basically "plug it in, make light". It's not dimmable with the supplied power supply. Ebay listing doesn't mention this, but the instructions do, LED breakdown is:

• 12 white (10k)
  
• 9 blue (470)
• 3 UV (430)
• 3 Green (520)

Overall, I'm pretty impressed. For a cheap ($67 US) light strip, it was made well, and lit up nicely. I question the usefulness of the greens, and kinda wish it didn't have them, but eh. Was easy enough to assemble, and the brackets screwed into my wall nicely. I mounted mine about a foot over the aquarium, and replaced 120W of DIY stars that I had built about 4-5 years ago, that started failing, because I did a terrible job of it.

Mounted at 1 foot, I'm pretty happy with the spread. It really lit up the tank. I just needed these to supplement the big lights on my 120G, which they did quite nicely. Good spread, good color, my corals pop a little more, and I'm good.

I also tried them out on my 800, because I'm looking to fill in a few holes in my lighting where the spots don't have good coverage. I tried just setting them right on the top of the acrylic in the front of the tank, where there is very little light, and they lit the bottom up nicely (3ft deep). Purely aesthetic at that depth, but it looked good. Being only 3" off the water though, you could make out the individual colors in the water at the top of the tank, so, not ideal, but they at least were able to illuminate the bottom sand at 3 ft.

Also tried them out in the back of the big tank. Took a PAR measurement with the main lights on 25% in a bad coverage area (basically getting ambient light) and read 60. Put the lights right on the 1" acrylic over that spot, and at 1 ft depth, read about 130. This was just with a single 3ft bar. Not super powerful, but the area looked good visually.

I'll reply to this post later tonight with some pictures of the 120 with the lights powered up. Overall, I'd say these are a good value. I suspect if you got enough of them, they would be decent lights. Just one is purely aesthetic, but I'm OK with that for this use. I will probably buy 2 more of the 21" ones for use on my QT tanks, and maybe 2 more of the 48" ones for some supplemental lighting on my 800. (still debating the 800).

Hope this is helpful to someone. I have no connection to this seller, just relaying my experience.

Thanks for the review, I'm a little late to the discussion but have bin looking @ these leds. Now that it's bin a bit sins you've had them. do you still like them?
Or should spend the extra cash on the RB or SB's? looking for something to put over my 50g lowboy frag tank. thanks to all how contributed to this thread..

 

[ravi197699]

these lights are ok for what they are selling for and lens does pretty good job pushing the light in tank, but they are not using the correct blue, if they use the deep blue color and remove lenses then these will putout nice color with wide spread, as it is these lights can't be mounted close to surface water and doing so will cause beam light effect as shown in the picture from 1 of the reefer, you will see individual colors of lights pointing in the display tank.. JMO

 

[oreo54]

Plenty of Royal blue in the whites......

 

[ravi197699]

this light will pop even more with deep blue led

 

[sawdonkey]

Anyone using these long-term? I see they sell the with all 470 diodes now. Anyone tried them? At $58 for a 4 ft bar, it might be worth considering.

I saw a guy on insta that was using them and it seems he was swapping diodes out and putting some 440s in. Can you open them up? It looks like the they are sealed and the glass panel is glued?

Regarding the power being put to the LEDs, how does this compare with the Orphek bars or other comparable bars?

 

[sawdonkey]

Well, to answer my own question, my Orphek OR3 150 (60 inch 42 dual 5W chips) is pulling 76 W. My 35 inch OR1 with 24 3W chips pulls 44W.

So....less than 2W per diode, not much better...and I had diodes burn out in one of the OR1s and the are sealed, so I couldn’t even fix it.

 

[MrPike]

I have some experience with these. I bought them at least 2 years ago for a maintenance customer. The tank is like a 250 gallon that sits on the floor, and on top is a slab of marble. The slab sits on feet that elevate it about 1/2 inch above the tank.

Anyway, there is a ton of humidity, and we burned through quite a few different led strips before finding these on alibaba.
I was not overly optimistic, but have been quite pleased with their longevity given the terrible environment they were placed. The tank has 4 of them in 4’, half are Actinic, other are the whites. Corals are softies and Lps and the light is plenty, tank is over 32” tall

Shortly after installing these I noticed orphek started carrying them and they are suspiciously similar. Also the SBar lights look close as well but who knows who copied who.

 

[garbled]

So just kind of a longer term update to this ancient post. I've had them installed since Feb 2019, so almost 2 years.

The ones on the QT tanks, (4ft version), still doing great, but I use them sporadically, so, far less usage.
The ones on the 120g tank (3ft version), have been in use every day for about 10hrs a day. One of them gets alot of salt spray. Zero problems, still light up, still provide light.

Overall, I'm happy with them.

 

[Indoor Reef]

So just kind of a longer term update to this ancient post. I've had them installed since Feb 2019, so almost 2 years.

The ones on the QT tanks, (4ft version), still doing great, but I use them sporadically, so, far less usage.
The ones on the 120g tank (3ft version), have been in use every day for about 10hrs a day. One of them gets alot of salt spray. Zero problems, still light up, still provide light.

Overall, I'm happy with them.

Thanks for all the info you shared here. I'm waiting on 2 medium size bars arriving at the moment. On the ones you received, what size is the fixing point on the bracket? I'm going to start thinking about possible mounting options while I wait for delivery.

 

[jtone_philthy_aquatics]

I have the 2 foot 470 blue and a 2 foot day light bar I got both off of Ali express directly from populargrow they arrived fast because it seems like they have some hubs around the country. They were only 32 bucks a piece. I got them in about 6 or 7 days. So far so good. I have them over a 40 breeder reef tank for supplemental lighting.

 

[DavidinGA]

So...did anyone actually verify which bar length is providing the highest watt per diode? Are the shorter bars actually more powerful than the longest one?