# how to setup 180 deg beam angle LEDs for best PAR?



## mitko1994 (Dec 12, 2012)

Hi everyone,

I have 3 - 50W LED floodlights above my tank (see: http://i.imgur.com/rM8Elu5.jpg). The seller told me they have a 180 deg beam angle (I know it's a very wide angle but I was stupid enough not to ask before hand thinking that all floodlights have 120 deg beam angles. The way they are setup right now I see that a lot of the light is just flooding the room and not going into the tank. What's the best setup in terms of positioning the fixtures w.r.t the water surface so I get max PAR out of them. I read that the wider the angle the less PAR at the substrate which makes me think it would be best to have them as close to the surface as possible.

What do you think?

Thanks
Mitko


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## wtac (Mar 17, 2006)

Contact the seller to inquire about lenses of 90-100 degrees. Otherwise you will have to fashion a reflector to mount inside the housing to get a sharper beam angle.


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## default (May 28, 2011)

I wouldn't worry too much about the par in your tank, your plants are all fairly low light demanding plants and would benefit from the low par. I'd be more concern about the over spill of light, perhaps a makeshift light guard could work?

Not sure if those lenses could be replaced? Where did you get the lights from?


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## mitko1994 (Dec 12, 2012)

I'm not too sure if they are benefiting from it because even easy plants that grow super fast for other people don't really grow well like sag and crypts. I got the lights off ebay.


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## solarz (Aug 31, 2010)

Get some alumninium foil and tape them to the sides of the lights to prevent spilling. It won't look too good, but it's effective.

Another concern is, do you know if those lights are suitable for plant growth? From what I understand, LEDs produce a narrow spectrum of light, so if they're designed only for illumination, they might not be producing the full range of spectrum necessary for photosynthesis.


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## mitko1994 (Dec 12, 2012)

They are "cool white" - 6500K if I remember correctly


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