Someone I know purchased an LED fixture off Amazon and I had the opportunity to take some PAR readings. This is the fixture http://www.amazon.com/Aquarium-120W-provide-natural-sunlight-seaweeds/dp/B0058RXPOS/ref=sr_1_2?ie=UTF8&qid=1311791171&sr=8-2. It looks a lot like the chineese version that others in the reef hobby are selling for hundreds more. I also took reading off the ones that are being sold in LFS and Amazons has better readings. In all fairness, the lfs fixture has 2w led's. Amazons has 3w led's.
AMAZON LED
Product Features (Copied from Amazon):
- Based on 55x 3W high power LEDs. Blue 25*3w LED; White: 30*3w LED
- 2 power cord system: 1 Cord controls the White LEDs and 1 Cord controls the blue LEDs
- Powerful 120W LED Aquarium Light can replace 400W Metal Halide Lamp, save 90% on electricity bills
- No need to buy additional expensive cooling system
- For use of fish tank lighting, seaweed cultivation, coral, fish, etc
Not mentioned on Amazon
- Power cords are detachable like on a computer
- 2 ON/OFF Switches. One for the White and one for the Blue
- Has an Aluminum type Reflecter
*NOTE: Please take into consideration that the numbers below will vary in different setup as some setups might have clearer water than others.
*NOTE: Readings started getting difficult at 14" depth cause of corals and rock work.
Fixture is 6" above water line
wl = Water Line
_________________________________________________________________________________________________
In water PAR readings
Water Line --------------- 670
Right below wl------------ 420
8" below wl--------------- 170
*14" below wl------------- 85
20" below wl-------------- 62
__________________________________________________________________________________________________
Out of water PAR readings
6" below fixture---------- 670
12" below fixture--------- 228
18" below fixture--------- 112
24" below fixture--------- 67
30" below fixture--------- 45
AMAZON LED
Product Features (Copied from Amazon):
- Based on 55x 3W high power LEDs. Blue 25*3w LED; White: 30*3w LED
- 2 power cord system: 1 Cord controls the White LEDs and 1 Cord controls the blue LEDs
- Powerful 120W LED Aquarium Light can replace 400W Metal Halide Lamp, save 90% on electricity bills
- No need to buy additional expensive cooling system
- For use of fish tank lighting, seaweed cultivation, coral, fish, etc
Not mentioned on Amazon
- Power cords are detachable like on a computer
- 2 ON/OFF Switches. One for the White and one for the Blue
- Has an Aluminum type Reflecter
*NOTE: Please take into consideration that the numbers below will vary in different setup as some setups might have clearer water than others.
*NOTE: Readings started getting difficult at 14" depth cause of corals and rock work.
Fixture is 6" above water line
wl = Water Line
_________________________________________________________________________________________________
In water PAR readings
Water Line --------------- 670
Right below wl------------ 420
8" below wl--------------- 170
*14" below wl------------- 85
20" below wl-------------- 62
__________________________________________________________________________________________________
Out of water PAR readings
6" below fixture---------- 670
12" below fixture--------- 228
18" below fixture--------- 112
24" below fixture--------- 67
30" below fixture--------- 45