LED conversion

ledman

New Member
I love the fact that every one is concerned about PAR but the real measure of light output Is PUR, which Is the Amount of USABLE light that is emitted by a light source. That is the true measure not to mention the fact that you water quality has an equal part in the coral growth equation besides your light output.
 

swimmer4uus

Member
Originally Posted by Ledman
http:///forum/post/3228638
I love the fact that every one is concerned about PAR but the real measure of light output Is PUR, which Is the Amount of USABLE light that is emitted by a light source. That is the true measure not to mention the fact that you water quality has an equal part in the coral growth equation besides your light output.
But can you actually measure the usabale range for corals? I think using PAR as the measuring device, is the best we have to compair sources.
 

reefraff

Active Member
Originally Posted by Ledman
http:///forum/post/3228638
I love the fact that every one is concerned about PAR but the real measure of light output Is PUR, which Is the Amount of USABLE light that is emitted by a light source. That is the true measure not to mention the fact that you water quality has an equal part in the coral growth equation besides your light output.
PUR isn't a huge factor. The critters more efficiently use light within certain ranges of PAR (PUR) but they still use it all.
 

mastertech

Member
Originally Posted by Ledman
http:///forum/post/3228638
I love the fact that every one is concerned about PAR but the real measure of light output Is PUR, which Is the Amount of USABLE light that is emitted by a light source. That is the true measure not to mention the fact that you water quality has an equal part in the coral growth equation besides your light output.
we could get a little more indepth if you would like. i was just waiting for a trigger to discuse some more technical aspects of light, growth and health.
PUR - photosynthetically usable radiation
PAR is a measurement of photosynthetic photon flux (area) density
(from wiki "Because photosynthesis is a quantum process PPFD is generally used by plant biologists, but W/m2 measurements are important in energy balance considerations for photosynthetic organisms"
PAR meter give us photon flux in a certain range of wavelengths and the unit of that measurement is PPFD. The PUR has to consider the actual photopigments involved (chlorophyll a, c2, peridinin for our uses mostly) and would therefore be more specific. PAR is more general, but still useful as it is easy to measure and compare.
PAR meters and lumen meter are much less expensive and are readily avail to folks like me.
there are other parameters that are probably as or more important ... like water quality, appropriate feeding, etc
the higher the light, the lower the nutrients have to be, otherwise you end up with lots of brown corals. apparently the xoozanthellae will overpopulate if you have high light with high nutrients and since they are green and brown it shows in coral coloration
some good reads and resourses use in my research. also some of these statements are summarys of conversation i have had with other members in out non profit organization.
http://www.personal.psu.edu/sbj4/aqu...osynthesis.htm
http://en.wikipedia.org/wiki/Photosy...tive_radiation
 

spanko

Active Member
I suggest you paste this in a google search
par38 par plots
The go to the first link for some good information .
 

reefraff

Active Member
DIALOG!!!!!!
Have you tried the LED's with no optics to see what effect you get?
I am doing 84 over a 120. The plan is to mount the LED's with no optics inside aluminum channel and using acrylic shields so I can keep them lower to the water. The channel which is 2x1 inch should somewhat focus the light into the tank rather than letting it scatter front to back where it wont hit the water. Might even try slipping in some of the 50 million T5 reflectors I have laying around

I am going to try
50 XR-E Royal Blues
8 XR-E Warm Whites
6 XR-E Q5 cool white (front row, no sense in lighting the floor so I didn't want the wide pattern of the XP-G)
20 XP-G Cool Whites
If it ends up too blue plan B is to throw in a row of 4 MC-E stars, that should brighten things up.
 

king_neptune

Active Member
Hows it comming?
Been watching this thread since inception. Curious if you have any advice in hindsight.
Im working with swimmer4us on his thread, hes helpingme design my own system for my 125 brick.
Feel free to jump in.
https://forums.saltwaterfish.com/vb/s...-Diy-led/page7
Once its all said and done, Ill post my own DIY LED build. THX for all your time spent on this project! It got me really moving in the right direction.
 
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