mr.wilson
.Registered Member
Very interesting - Orphek apparently used very tight optics to produce large PAR values. This however resulted is a very small coverage area. Very few tanks would need (or want) 350 PAR on the substrate (and that's at 30"!) That amount of PAR confined within the footprint of the module is all but unusable unless the light was elevated much higher above the tank (not possible on Peter's build), was refitted with wider lenses and/or had dimming capability (sadly not available on the Orphek.)
The fixture is clearly a PAR monster - That 900 PAR measurement recorded near the surface is likely ~20% greater due to PAR meters underestimating the bluer light output of LEDs.
Assuming you like the quality of the light, you'll need to stick some "coke-bottle" lenses on that thing ShawnYou may also have a challenge in balancing PAR, coverage and aesthetics. At equal PAR, LED light appears much "less bright" in comparison to MH or T5. Wider optics will increase the coverage area and more evenly spread PAR - but it may appear unacceptably dim from an aesthetic point.
Oh good, it's not just me. I couldn't figure out why the Orphek produces 1300 lumens while the brighter looking MHL is half of that. PAR was also half but appears brighter.
I noticed that the manufacture of the light in China uses 120˚ optics on their grow lights. I will contact Orphek and see if they can ship me some of these.
Yes, we hit the ceiling so we can't spread the light more. The light is currently about 12" above the surface of the water. To be fair, the light is suspended over the 1" acrylic top brace, but so are most of the other lights.