R
rmcc-luke
very nice post!
cheapo, diy pyranometer meter (from other incarnations):Man a quantum light meter starts at about $200 (http://www.specmeters.com/Light_Meters/Quantum_Light_Meter.html) that measures PAR, gonna have to get one someday, but I'll still be one of only a couple guys here with them. Lumen meters are everywhere and cheap so thats what everyone uses for reference. Any estimates on how many PPFD a 1000W HPS puts out at 22" or so from the bulb?
hope this helps. enjoy your garden!quantum meter
measures the number of electromagnetic energy units (photons) available on the leaf surface in units of microeinsteins per square meter per second (ue/m^2/s).
radio meter
measures the amount of radiant energy available on the leaf surface in units of watts per square meter (w/m^2).
pyranometer
measures par (photosynthetically active radiation) watts/m^2.
measuring sunlight at earth's surface:build your own pyranometer:
http://www.pages.drexel.edu/~brooksdr/DRB_web_page/construction/pyranometer/pyranometer.htm
I'm confused, can your room not drop below 1450 or is your burner circuit always live? Plants give off O2 at night and do not uptake almost anything, including CO2 so it's almost entirely wasted on them in the dark. I can post you some research papers on this if you'd like.
I don't know about the entire length, seems to knock it down at least a couple of days, but what's really noticeable IME is the onset of flowers and how much more quickly they develop. IMO the biggest visible changes are from weeks 1-3.Most seem to agree that flowering is about 5% faster with CO2.
I've seen multiple sources stating what you said. Ed Rosenthal. The back of a CO2 controller box that had a timer that turns off the CO2 at night "because CO2 is not used at night".
I would really like to see those research paper on it, because that is not how I learned it in my college botany class in the eighties.
Photosynthesis is divided into two "reactions:" the light cycle and the dark cycle: photophosphoryation and the calvin-benson cycle. It is now known as the light cycle (because it requires light) and the light independent cycle (still the calvin-benson cycle) because it works in the light or the dark.
That's what I learned 20+ years ago. I understand that scientific "facts" often change. Can you enlighten me?