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Using PAR instead of lumens

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I was wondering if you were going to switch over and start using PAR instead of lumens when referring to light measurement since plants don't see lumens really. PAR is the reading for plants from what I have learned.
Also if there are any recommended levels of PAR and DLI for different photo periods in the grow cycle like 18/6 and 12/12?
 
I don't get too scientific with all the different terminology. I use 400w T5 for vegging and 1000w HPS for flowering. It grows my weed well. Does 't matter if it's PAR or Lumens. K I S S .
 
Yup- you have to use PAR values for LED's because lumen's only come from white LED's as I understand. Most LED manufactures will post the PAR value at a certain distance. (see below for a 150w UFO LED)
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Oh trust me I have learned more about PAR and DLI in the last few months than I ever thought I would. Google PAR for tomatoes and see how much university based data pops. Im just looking for more. I also found out there is such a thing as too much light the hard way. My COB DIY kit will throw well over a PAR reading of 950-1000 at 25 inches. Way to much. Keep it turned down to around 325 for veg. Id just like to see more grow info going that way. PAR is measurable by all light sources including fluorescent, HPS and LED. Apogee quantum sensors are a useful tool and enlightening as to how much light your really putting on your plants. They are not cheap but worth it to me. Even for a small grower like me.
 
Stewart169 said:
Oh trust me I have learned more about PAR and DLI in the last few months than I ever thought I would. Google PAR for tomatoes and see how much university based data pops. Im just looking for more. I also found out there is such a thing as too much light the hard way. My COB DIY kit will throw well over a PAR reading of 950-1000 at 25 inches. Way to much. Keep it turned down to around 325 for veg. Id just like to see more grow info going that way. PAR is measurable by all light sources including fluorescent, HPS and LED. Apogee quantum sensors are a useful tool and enlightening as to how much light your really putting on your plants. They are not cheap but worth it to me. Even for a small grower like me.
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Just curious, when you say a PAR reading of 1000, what unit of measurement are you using? I wrote a little bit about PAR vs lumens because this is also something I'm also really interested in. If you're a fellow light enthusiast, I'd love to hear your thoughts on it!
 
Don't make my whip out the dissertations on lumens par photon flux Photon flux density & uMols. If you're into growing dank buds, familiarize yourself with the science of light.

Bottom line is PAR matters for all lights when growing.

If you use only hps or only mh, your veg/flwr cycle is lacking in frequency and so you could be doing better for your plants. Understanding light is as important as understanding the rest of growing.
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NebulaHaze said:
Just curious, when you say a PAR reading of 1000, what unit of measurement are you using? I wrote a little bit about PAR vs lumens because this is also something I'm also really interested in. If you're a fellow light enthusiast, I'd love to hear your thoughts on it!
Click to expand...

I refer to PAR as measured by a quality and reliable quantum meter like this http://www.apogeeinstruments.com/mq-200-quantum-separate-sensor-with-handheld-meter/
With my light cranked to 100% @ 28 inches the meter will show 900-1000 depending on the placement under the light. Plus using university research data I am trying to stay with a DLI of 20 for early veg and 25 late veg and flower.
 
PPFD is the unit of measure. The instantaneous reading and averaging it over the photoperiod. I didn't just make it up. I have spent hours reading on it and don't pretend to have the background to be an expert. Like I referenced the data from multiple agriculture programs and major universities that provide data to the farmers of the US and world are the ones doing the research. Id love to find some info from the real pros in the cannabis industry who grow for a living on what kind of light levels work best for them.
There is FAR too much money at stake for them to just hang lights and say its good to go and not record data just like they do with soil or hydro analysis. Would you not agree with that?
 
I agree 100%, but I just wanted to know what unit of measurement it's using so I can compare against journals because this is also an interest of mine. Is it measuring the PPF in μmol·m[SUP]−2[/SUP]·s[SUP]−1[/SUP]? Or in W/m[SUP]2[/SUP]? It should say in the manual or it might be printed somewhere on the device itself. I'm curious, does it have different modes for different light sources like sun/incandescent/high pressure sodium/etc? I've always wanted to get my hands on one of these! How did you end up finding it?
 
Yes, but it doesn't say what unit of measurement it's using. You know, like I could say I have 1000 purples, but that doesn't mean anything because purple isn't a unit of measurement.
 
Yes, but lumens is a unit of measurement. I can say something is giving off 1000 lumens. But you can't say 1000 PARs because PAR is not a unit of measurement. Aren't you curious what your instrument is actually measuring? I think it's measuring in μmol·m[SUP]−2[/SUP]·s[SUP]−1[/SUP] which is basically the amount of photons per square meter per second, but there are other ways to measure light like W/m[SUP]2[/SUP].

It seems like if you want to compare to journals or other growers you would want to know what you're comparing, right? Otherwise you're comparing apples to oranges.

It's like if I said the size of a ruler is 10. Do I mean 10 inches, 10 cm or 10 feet? It's unclear what is even being measured without the unit of measurement. Do you see what I'm saying?
 
I think I know how to put this in simple words. "Visible light" is a term we use to refer to the range of electromagnetic radiation that we perceive. Now "PAR" is the plant "visible light" referring to a different range of the spectrum. Many light that we see and some we don't. So just as some light bulbs are made to produce the light we see. There are light bulbs that produce light in the PAR range. Regardless of the intensity. Which nebula is asking about. And its measured in diferent units :)
 
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