12х LED assembly for reef tank v4.1R
Version 4.1R Product code: 12xV4.1R

The 12xV4.1R LED assembly is an economy light source for your reef tank. Its creation was the outcome of years of research, as outlined in our article
Light in the Reef Aquaria


Availability:  Out of Stock

Differences from Rev. 12xV4.0R.
1. The LED chains are now connected between X1 and X2. As a result, the LED assemblies can be easily connected in series. This simplifies the assembly of a LED fixture, especially when using our 2x LED drivers with a high voltage power supply: up to 5 LED assemblies can be connected in series. 

2. An MCPCB with improved thermal path has been used. The LEDs can now be used at their maximum current.

3. Significantly increased quantity of emitted radiation of all types of LEDs, excluding the Blue LED.

Color Connectors
of chain of
Max. current Max. voltage
on the chain
Wavelength /
Color temperature
LED emitter type
Violet X1 pin1 -> X2 pin6 800ma 10.8V 400-410nm
C35L-U-A 400-410nm, 480-520mW @ 350mA
C35L-U-A 410-420nm, 480-520mW @ 350mA 2pcs
Blue  X1 pin2 ->
X2 pin5
1000ma 3.6V 460-470nm Semileds C35L-BN-A, 30.6-35.2lm @ 350mA
Turquois X1 pin3 ->
X2 pin4
1000ma 3.6V 510-520nm Semileds C35L-CN-A, 80.6-87.4lm @ 350mA
Cool White
Neutral White
X1 pin4 ->
X2 pin3
1000ma 10.8V CCT:8300-10000K
Semileds C35L-W0-A,130-139lm @ 350mA 2pcs
Semileds C35L-W1-A,122-130lm @ 350mA
Red X1 pin5 ->
X2 pin2
700ma 2.8V 620-630nm Semileds C35L-R, 56.8-62lm up @ 350mA
Royal blue X1 pin6 -> X2 pin1 1000ma 10.8V 440-445nm Semileds C35L-DN-A, 560-600mW @ 350mA 3pcs


Total power consumption, W: ​ up to 39
Board dimensions:  
             Length, mm / in   70 / 2.76
            Width, mm / in 60 / 2.36
            Height, mm / in 7.4 / 0.29
Mounting holes diameter, mm / in 3.3 / 0.13
Mounting holes spacing, mm / in 47.5 / 1.88
Weight, grams / oz 33 / 1.16
Completely solderless assembly. Matching connectors are included. YES

The LED assembly must be used with matching LED drivers. If using with ReedLedLab controller and drivers, control channels on the drivers can be configured by jumpers. Instructions.



  • Full-spectrum
  • Small dimensions (size is determined by secondary optics)
  • 12 power LEDs, Latest C35 generation by Semileds
  • 8 LED types combined in 6 independent channels, to provide unique control over spectrum
  • Sufficient radiation in true violet range, to provide for best coloration, fluorescence, and coral growth*
  • Minimized “Disco effect”, due to densely populated LEDs and the use of hybrid secondary optics with diffusers
  • A completely solderless solution simplifies the assembly
  • 100% quality control for all LEDs on the assembly



“*” no competing solutions were available on the market by December, 2014.

Make a DIY LED fixture using our LED assembly: Video Tutorial:

Note: – the tutorial was made using rev. 2.2 of the 6-channel LED assembly and a different connector. You can also watch our video tutorial on how to use the new connectors.

Using the KRP crimper tool:

Theoretical and practical aspects of LED lighting

What type of light is available to corals in nature? What type of light do corals require for growth and for best coloration? Under what spectrum will your reef tank look its best? You will find the answers to these questions in this section.

All you need for DIY

Do you want to build a DIY LED fixture that would best fit your tank’s requirements, using the state of the art technological achievements and the highest grade components? You will find the answers to these questions in this section.


Building a DIY LED fixture has never been so easy! Find the answers to many questions that hundreds of others have asked. Everything you want to know about building DIY LED fixtures is available in this section.