Burnt acro tips under LED

[alton]

I hate you to have to buy another meter but what I have learned with LED you need to have both PAR and Foot Candle Meters. We all know what a PAR meter is for but a foot candle meter measures how bright a light can be or its intensity. I learned this the hard way with a Marineland Reef Capable LED and burning a Green Birdsnest. PAR was only 200 on top of the tank, but my foot candle meter measured 4000 (Equal to a 400w MH). My Radium metal halides are 2500 footcandles with a PAR reading of 2000 on top of the tank. My BML fixtures are also very close in comparison when reading both PAR and FTC. What is funny if you go back a couple years you will see most complaining and saying PAR meters don’t work with LEDS. But today most turn their LEDs down because of too much PAR. In some ways LEDs and MH are the same if you are measuring blues like in the 20K range not much PAR, but once you add Reds and Yellows in the 7K to 12K range your PAR goes up big time, no different than in lamps. I run the PAR meter loan program for our local reef club and for most they are very happy with their PAR readings from their manufactured led fixtures, the only complaints have come from those that built there own.

[CTaylor]

Interesting, Alton.
As far as the lenses, RapidLed has only 80's, no 90's or 100's. Will I be ok with this? Or should i go to
http://www.aliexpress.com/item/cree-...763408591.html

And get the 90's from there. They are chinese made, if that matters (usually chinese is bad, right?)

[CTaylor]

^bump

[Aquarist007]

Originally Posted by alton

I hate you to have to buy another meter but what I have learned with LED you need to have both PAR and Foot Candle Meters. We all know what a PAR meter is for but a foot candle meter measures how bright a light can be or its intensity. I learned this the hard way with a Marineland Reef Capable LED and burning a Green Birdsnest. PAR was only 200 on top of the tank, but my foot candle meter measured 4000 (Equal to a 400w MH). My Radium metal halides are 2500 footcandles with a PAR reading of 2000 on top of the tank. My BML fixtures are also very close in comparison when reading both PAR and FTC. What is funny if you go back a couple years you will see most complaining and saying PAR meters don’t work with LEDS. But today most turn their LEDs down because of too much PAR. In some ways LEDs and MH are the same if you are measuring blues like in the 20K range not much PAR, but once you add Reds and Yellows in the 7K to 12K range your PAR goes up big time, no different than in lamps. I run the PAR meter loan program for our local reef club and for most they are very happy with their PAR readings from their manufactured led fixtures, the only complaints have come from those that built there own.

Great post. There is no radius of coverage with the double brights.. I would think that would make a big difference with foot candles.. Just like using a magnifying glass. IMO those lights were the worst built on the market. I supplied 18 pairs of them to clients and have replaced them all at some point