Par Readings for LED Fixtures

[xiaan]

So it is a nice rainy day so since i have a PAR meter I deiced to test several LED fixtures that I own here are the results.

PAR readings are taken with a Apogee Quantum MQ-200 PAR Meter 7" from fixture.
Watt readings are taken with a P4400 Kill A Watt meter.

All fixtures (except the AI SOL Blue it is brand new) have been running for at least a month (some of the Reef brights and the PAR 38 have been running for a year).

The best readings where taken from my generic PAR 38 fixture but it has a very high destiny of LEDs where the other two fixtures are more spread out. the density of the LEDs will effect the readings.

The next best fixtures were the AI SOL giving a nice PAR reading or 1600 these had no controller on them so they where going at 100%.

Finally the Reef Brights not surprising that they cam in last as they are under-driven for more longer life of the LEDs. But the 5 fixture setup is still quite good as it has been running on my frag tank (mostly SPS) for the last year and I have been seeing good growth. I just reasly switch over to the SOL White for my Frag Tank and at 50% intensity is is cooking my frags.

If I get more time I might also test my 6x39W ATI Fixture at the same paramaters and see the results.

[xiaan]

I just tested my 6x39w ATI Sunpower for some baseline results bulbs have been in the fixture for 6 months (Since Jan)

2 Bulbs 74.6W @ 161 PAR
4 Bulbs 163W @ 387 PAR
6 Bulbs 240W @ 550 PAR

[Hookup]

Any way to estimate the LED density per fixture?  LED's per linear foot maybe?

Great tests. Extremely cool use of a lazy rainy day.

[Rybren]

I do believe that I've read that the Apogee under-reads blue LEDs, so your LED PAR readings are likely on the low side.

[xiaan]

I do believe that I've read that the Apogee under-reads blue LEDs, so your LED PAR readings are likely on the low side.

That is what I have also read but I do not know by what percent I think that is why it is hard to compare non LED fixtures with LED Fixtures. But It should be no problem comparing LED to LED.