DIY LED light for JBJ 28 cube

[icejam]

I started working on LED lights to replace the MH light in JBJ cube.
All parts started to arrive slowly. My design is loosely based on Hydra 26 and Atlantik lights.
All LEDs are 3W on 20mm pcb in 7x7 grid configuration - haven't worked out the exact spacing yet.
That gives just shy of 150W of power, which is probably an overkill for 28 gallon tank.
I am planning on slightly under-powering the LEDs (80%ish) so total power will be closer to 120W mark. I am thinking 4-7 channels maybe some zones, all driven with Arduino.
No idea on the spectrum or luminance yet until the prototype is complete.
I will not be able to measure PAR - just too expensive

Let me know if you have any suggestions on LED placement.

 

[chipmunkofdoom2]

Looks like a decent layout. 3W LEDs are pretty powerful to have spaced out that far apart though. Black box LEDs are spaced similarly, use between 750 - 1000 mA of driving current, and cover a much larger area.

You may want to consider using some sort of diffuser to get better spread and blend. I think with LEDs that powerful spaced so far apart on such a small tank, turning them down is going to create a good bit of shadowing. Adding a diffuser will likely cut the intensity and spread out the light a bit better.

 

[icejam]

I have various lenses on order from 15 to 100 degrees. And a fresnel lens from and old TV. I might offset alternating rows for better coverage.

 

[User1]

You ever consider looking at the nano box 3.1 or maybe something from blue acro?

 

[icejam]

Nano box array only, comes to $90 with shipping, or $320 for a complete small kit.
I am hoping not to spend more than $50 on the whole project.
Hence everything is DIY.

 

[icejam]

Time for an update.

I discovered it's virtually impossible to blend colors nicely in aquarium LED light. No matter which lens / diffuser combination I used, I could see separate colors on sandbed and the disco effect was driving me crazy.
So after dozens of combinations and countless experiments with power levels this is what I decided to go with.

I mounted the LEDs on the original reflector from JBJ lid. LEDs are secured with zip-ties over the heat conductive pads.
Wiring is passed through the same holes as zip-ties for cleaner look.
LEDs are in groups of 4, powered with 13.5V at 650mA. That gives me 7 control channels.

The back of the reflector has three 1in x 0.5in heatsins running the full length of the reflector.
I run lights 24x7 for couple of days monitoring amperage and junction temperature and I do not need any active cooling

I do not have PAR meter and can't find any of my instruments (recently moved across the world) to measure anything of value.
My lux meter reads my aquarium lights at 200, but it also reads my kitchen light at 10000+ so I would say it's broken.

This is my new light schedule:

I am unable to control all the channels fully yet as I am still waiting for some parts to arrive.

I forgot to take pictures of finished product - will update tomorrow.

 

[icejam]

I should probably mention costs:
LEDs $0.30 x 30
Drivers $1.99 x 7
Heatsinks $3.87 x3
12v power supply I got for free but new would be $15
Assorted wire, zip-ties and miscellaneous - free.
Control gear - arduino, RTC, relays, optoisolators, etc less than $10.

All came to well under $50.

 

[Sean Landholt]

Do you have a picture of the light over the tank? I have a kessil tuna blue over my jbj 28 and I want to so more light so I am checking my options.

 

[theatrus]

Time for an update.

I discovered it's virtually impossible to blend colors nicely in aquarium LED light. No matter which lens / diffuser combination I used, I could see separate colors on sandbed and the disco effect was driving me crazy.
So after dozens of combinations and countless experiments with power levels this is what I decided to go with.

I mounted the LEDs on the original reflector from JBJ lid. LEDs are secured with zip-ties over the heat conductive pads.
Wiring is passed through the same holes as zip-ties for cleaner look.
LEDs are in groups of 4, powered with 13.5V at 650mA. That gives me 7 control channels.

The back of the reflector has three 1in x 0.5in heatsins running the full length of the reflector.
I run lights 24x7 for couple of days monitoring amperage and junction temperature and I do not need any active cooling

I do not have PAR meter and can't find any of my instruments (recently moved across the world) to measure anything of value.
My lux meter reads my aquarium lights at 200, but it also reads my kitchen light at 10000+ so I would say it's broken.

This is my new light schedule:

I am unable to control all the channels fully yet as I am still waiting for some parts to arrive.

I forgot to take pictures of finished product - will update tomorrow.

Word of warning on zip ties: they will break from thermal cycles.

 

[icejam]

Word of warning on zip ties: they will break from thermal cycles.

I am using nylon zip ties with steel wire core - no risk of breaking. But I wouldn't stress about regular zip-ties breaking in 30C 12h cycle.

 

[icejam]

Do you have a picture of the light over the tank? I have a kessil tuna blue over my jbj 28 and I want to so more light so I am checking my options.

Yes I do but I am working away from home for next couple of weeks so might not be able to post pictures [I'll try to vpn home on Monday and see what I can do]

 

[theatrus]

I am using nylon zip ties with steel wire core - no risk of breaking. But I wouldn't stress about regular zip-ties breaking in 30C 12h cycle.

I have a lot of broken zip ties to show otherwise, usually fatigued at the tight corners

 

[icejam]

Do you have a picture of the light over the tank? I have a kessil tuna blue over my jbj 28 and I want to so more light so I am checking my options.

This is what I found so far. The LEDs replaced stock halide light - the aquarium looks like a regular JBJ from the outside (I have to use a lid because having cats is great).

Also here is my arduino based PWM control solution:

I will try to get the pictures of the tank with the LEDs off in the day light.

Hope that helps.