As I was about to contemplate placement of some 12x12x18 tanks, it occurred to me to wonder how best to light them. I happen to have a couple different types of light around so I thought to try them all. The first was a standard 14W CFL @ 5000K. The second is a 13W florescent straight tube @ 6500K. The last are 3 concentric rings of 75 3528SMD LEDs @5000K.

Well obviously the florescent straight tube just looked bad and blue. Perhaps a different bulb might work, but my search was done. The LED’s good great, but produced a flatter light.

This came back to CFL’s vs. LED’s. CFL are easy enough to talk about. The are not many kinds. But for LED’s I only wanted to deal with 3528 or 5050 SMD. They say 5050 is 3x stronger than one 3528 and best to bright application. But 3528 dissipated heat better in the long run.

My second test was on some recent rebuilds which were already planted and were 21.6″ tall. taller as compared to standard 18″ tanks. Regardless, side-by-side the light difference was barely noticeable while viewing the plants. Intensity of the light hitting the substrate below was different.

I don’t have a way to measure lumen. So I capture ambient light and use it to know the proper F-Stop needed for shoot a film at 24fps with 320ASA film. Some say this is a comparable to the human eye as you get. So I setup my light meter and her are the results:

The first light meter registers the light from the 75 LEDS. It’s telling me I need an F-Stop of 2-8-2. The second meter says F-Stop of 2.8-5. Which means the 14W CFL is giving off more light. But not all that much more. And I think with a quarter more LEDS, I could create a light disc that had what’s needed to replace the CFL.

Quite frankly, I just want a flat board of light to place above my tank. I won’t want extra height if I can avoid it. And I see this happening.

From dinodirect.com I can order white ring lights of 3528 SMD LEDs.

• 60mm – 15leds – $6.18 x2
• 80mm – 24leds – $8.18 x2
• 100mm – 33leds – $7.99 x2
• 120mm – 39leds – $11.59 x2

This makes for a CD sized disc of 111 3528 SMD LEDs  @ the cost of $33.94 for two such rings. The result would do slightly better than a 14W CFL.

At about $17 + extras to complete it, is the price right? Or are 5050 SMD LED a better option?