Par readings you judge

ms705jk · Oct 4, 2014

Today I rented a Par meter for these cheap Chinese light panels I got on eBay. After taking tons of measurements I felt compelled to share them with y'all. Some of you I think will be very surprised. All measurements are with both switches in the on position and dimmer knobs at the same percentages. Measurements are distant from light and center of tank. In water. Lights 10" above waterline.
AT 25%
14" 150
18" 111
22" 85
26" 80
30" 75
AT 50%
14" 297
18" 260
22" 247
26" 222
30" 205
AT 75%
14" 556
18" 549
22" 462
26" 409
30" 373
AT 100%
14" 959
18" 740
22" 680
26" 637
30" 530

Eric B · Oct 4, 2014

That's the lights I run over my 300 gallon tank. I run 6 of them over the tank after switching from another similar led fixture and I saw better color, growth and polyp extension from these new lights. I run them all at 100% as I had done with the other lights.

joshbbert · Oct 4, 2014

Very helpful ty

ritter6788 · Oct 4, 2014

Is that with optics or without?

ms705jk · Oct 4, 2014

ritter6788 said:
Is that with optics or without?

I'm not to sure what you are asking. The lenses are 60 degree I think

ritter6788 · Oct 4, 2014

ms705jk said:
I'm not to sure what you are asking. The lenses are 60 degree I think

That is what I'm asking. The numbers seem high so I thought it must have a narrow optic. I'd be curious to se the par results with the same light at 90, 120 and no optics. My theory all along is that people's issues with leds are narrow optics and running them at too high % or wide/no optics at too low %. Looking at your numbers I'd run those lights at about 50% depending on the tank depth. Possibly 75% with 90 degree optics and 100% with 120 degree or no optics. Just rambling out loud here.

Thanks for posting.

ms705jk · Oct 4, 2014

No problem. I felt like the 60's would give me the best lifespan. I'm acclimating from about 20 percent, hoping to get to around 50 percent and stop there. My guess is it'll take around 3 weeks to get there. The tank us 14"l x 14"w x 20"h. This is plenty of light

Eric B · Oct 5, 2014

Mine like these only have 90 degree optics and the old lights I had did have 60 degree optics but were mounted higher than these with 90 degree optics. I measured with my par meter and on the sand bed with the new lights I get around 200 par running at 100% and the older lights I think I was in the upper 200's on the sand bed and they were mounted higher above the water to try to get the light to blend more with the 60 degree optics (so it didn't look like a spot light of different colors over the tank). I do find that the color is better under the newer light with the 90 degree optics for some reason and growth rate is about the same with both lights.

g6gang · Oct 5, 2014

Where do u rent one of these par meters? I was thinking of buying that Senseye Reef pH/par meter thing for $199.

Rob&Gab · Oct 5, 2014

Those reading I see at 100%. 14" is 959 par , is that 14" above the water and that's what it's reading at the surface? Or 14" below the water level. If so how high do. You have it hanging?

Rob&Gab · Oct 5, 2014

Also what par meter were you using ? The apogee200 is a really good one. I would not use or trust that senseye PH/ par meter .

ms705jk · Oct 5, 2014

g6gang said:
Where do u rent one of these par meters? I was thinking of buying that Senseye Reef pH/par meter thing for $199.

My lfs has one they rent out for $25

ms705jk · Oct 5, 2014

Rob&Gab said:
Those reading I see at 100%. 14" is 959 par , is that 14" above the water and that's what it's reading at the surface? Or 14" below the water level. If so how high do. You have it hanging?

The light is 10" above the waterline and 4" deep in the water. All the measurements are from the light down. 30" would be the sand bed