Premium Member
I am just getting into looking to do my own DIY LED project. I know where to get most everything I need. My question (for the time being), how many LEDs do I need? I currently have a 6x39w T-5 Current fixture over my 40g Breeder. My tank primarlly houses SPS with an LPS garden on the bottom (no sand!). Also, is there any way around a Buckpuck driver, is there plans to make my own?

Thank you!


New member
Most projects i have seen advocate a maximum of 2.5" spacing between LED's, before you start getting spotlighting/coverage problems. Buckpuck is not the only driver out there - meanwell, kai domain, recom are others you can check out. You can DIY your own driver as well. I would imagine however that unless you know what you are doing it's not worth the hassle to make your own driver, especially for a 40g. For a larger tank the cost savings might be worth it.
Unless your time is worth pennies per hour, I'd suggest an off the shelf driver for a tank that small, as did g8gxp. The up front time to design and test a driver (even if you're following a reference design or someone else's project) is gonna be pretty huge for such a low number of drivers. One of the only reasons why I'm DIY'ing drivers is because I'm going to need 15 - 20 of them on my next tank. At that point, it makes sense. :)

40b breeders are fairly shallow, correct? I'd stick with ~30 LEDs, which will put you around 20 square inches per LED, just about right for a shallow tank. (I don't know the actual dimensions of a 40b so this is pretty rough.)