Originally Posted by TommyP
So someone in my area is selling a 48" reef marineland led
system but from the info he provided to me it seems to be only 8 blues and like 48 whites only 1w leds a little over 3000 lumens. Why is this listed as reef capable? If its not 3w LEDs? Or is this ok?
Most first generation aquarium LEDs produced about 70 lumen per watt. Modern and more efficient LEDs are now exceeding 130-150 lumen per watt (Cree). Bridgelux are good too, but Cree are better. These Marineland are about 53 lumen per watt. Crap.
Lumen is a measurement of total light transmitted, while PAR is measuring the light in the Photosynthetic range only (a better measurement).
Final thing on light, it doesn't matter ANYTHING about how many point sources you have for the light. That is to say, if you have 3 x 1 watt LEDs that have the same efficiency as 1 x 3 watt LED
which then produce the same amount of PAR at the combined source, they will have IDENTICAL, SAME, MATCHING, EQUAL light penetration at 24" under water. Anybody who says anything different does not know anything about light transmission.
That being said, most 3 watt LEDs are more efficient than 1 watt LEDs.
I only bring this up because every now and then someone makes the incorrect statement that comparable 3 watt LEDs will penetrate better than 3 1 Watt LEDs, as if light were a bullet. WRONG!!!