DIY move from T5 to LED

[NatureBoy]

Having been inspired by the light in this natural pool:


and in need of a summer project, I've used this tutorial to build my understanding on DIY LED lights:


After a couple of days procrastinating over where to buy I went with
http://www.led-tech.de/en/High-Power-LEDs-Cree/CREE-XB-Series-c_120_185.html

I ordered 20 Cree XB-Ds, to run in parallel series from a Mean Well 1.4A 9-42V constant current source.
Should give something similar to 4 Aquaray Grobeam 600s which also use the XB-Ds

Tank is L42"XH22"XW18", CO2 injected, daily macro ferts

If I put LEDs in one series I will fry the lights (they can take max 1A),
but 2 in parallel (running at 700mA each) should give me close to 6500K and a fair whack of lumen. Not sure how many of the 20 LEDS I will use in each series (min 4, max 10 to stay within PSU voltage drop off limits 9V-42V), trial and error I guess over desired output.

If too bright I can run in 3 parallel series each at 467mA, and at minimum in 4 parallel at 350mA. (not gonna go with dimmer for this first phase just to get the basics sorted)

Got a big chunk of aluminium from a local welder / metal fabricator to form the heat sink for a tenner, I think it's overkill but all good for a first run.

Mounting will be by adapting the existing hood, removing the lid but keeping the sides to keep the overall cabinet / hood design. Will take pics when the LEDs arrive from Germany.

I plan on placing lens in clusters on the heat sink, some unlensed for spread at 120degrees, some with lenses to punch to bottom and enhance the point source look, my hope is to create as natural a shimmer as possible and nothing too jittery.

So far cost total cost is £90

 

[GlassWalker]

Sounds like a fun build and you know what you are doing. Don't under-estimate the heatsink and it'll be fine. I haven't watched the videos, but if you like the shimmer effect bright sources over a disturbed water surface will provide that. I found I didn't like it too strong, so multiple lower power sources will help even that out.

 

[NatureBoy]

Sounds like a fun build and you know what you are doing. Don't under-estimate the heatsink and it'll be fine. I haven't watched the videos, but if you like the shimmer effect bright sources over a disturbed water surface will provide that. I found I didn't like it too strong, so multiple lower power sources will help even that out.

cheers, I've done lots of reading up, but if it's anything like the airfix kits I used to do it'll get messy pretty quick.

 

[GlassWalker]

The thing I found when doing builds in the past is they always take longer than expected... especially the mechanical side of it. Strictly speaking, I never completely finished my first build although it has been in use for a long time now. Wanted a splash guard as it is over an open tank.

 

[NatureBoy]

LEDs arrived super quick from Germany, ordered last tuesday and arrived friday!

wired up all 20 cree xbds into 2 parallel series set onto aluminium heatsink (soldering pretty ropey but all tight and fixed), mounted the heat sink onto part of old hood. switched on and bingo 20 bright leds!

think I will now buy some lenses for them but so far so good

 

[mr. luke]

Pictures

 

[NatureBoy]

Here are some of the build photos, it's worked out really well. A thing I'm really pleased about is that the lights don't emit as much heat down on the surface of the water so I can maintain 25 degree temps year round which was a major problem in past years.