LED DIY stuff

It's gonna be a Dimmable fixture so i can change the output on the lights. thing is, I'm still lost on the size of heatsink I'll need. This is going to be my false wall that I'll be building. the tank itself is 11.75" back to front, 23.5" left to right, and 15.5 top to bottom. I've been told that I won't need optics, is this true?

I still have a ton of questions and I have no idea where to start besides my kit of 36 LEDs.

 

A 4"x18" heatsink should cover you nicely. At that depth, I'd run 80deg optics.

 

In their kits they only offer 60*optics. Would this be alright if I spaced them out enough?

 

and would the 7.1" by 15.8" heatsink be alright?

 

Eh, not so ideal, and on the contrary. You'd need to use more diodes closer together and dim them down more. Otherwise, you'll get spotlighting. If you can't run ~80deg optics, I'd rather use none.

That's really wider than what you need on a 12" tank, and the 16" is gonna be a little short at the ends of the tank. Try heatsinkusa.com

 

Will I need a cooling fan?

 

That's a bit of a debatable topic.

My stance is they're cheap insurance. Cheap to buy, cheap to run, and certainly cheaper then burnt diodes.

 

Alright. So a fan is optional. I was thinking about building a small canopy to house my lighting.

 

I emailed rapidled the same exact question. the response I got was that an 18 LED setup using 10 RB and 8 cw on a 4.25x16" heatsink with no optics if setup 6-8" above the water. if setup over that hieght, then use 80* optics.

I would highly suggest a cooling fan, even a small one. though the larger you go, the lower the speed has to be to push the same amount of air. i myself will be building my canopy and wiring in a small 80mm computer fan to a 5v cellphone charger.