You would think, but the Rapitest meter says otherwise, and I do grow plants with the 5w LED bulb. For those on a budget, it's a handy item, the Rapitest. An interesting thing I learned is how little light plants really need, 5000 fc. Maybe dim light distributed around the canopy would be better than using very high wattage above to try to blast through the upper layers.
Get a better meter, that one is obviously giving you bad measurements.
Can't afford it. I'm a poor person. This one seems to suffice anyway. It eased my mind that the minus green filter didn't cut too much light out from the HPS.
don't feel bad. I use the same meter for relative measurements to insure I have uniform coverage . mine only goes up to 2000 but I don't know what its calibrated in. silicon photo cells have a response curve that matches the quantum curve so the longer the wavelength the higher the reading for a given input power and cheap light meters have no filters to modify the response so 1 watt of light at 700nm will read as 1.75 times the power of 1 watt at 400nm. as long as your 5 watt LED does a good job of "sprouting" clones nothing else really matters.people who pretend to understand quantum theory are very entertaining to those of us who do understand it.( I don't believe it but I do understand it
)the only thing that really matters is how well a light grows plants. and that is effected by many factors. light is only one of them. some strains grow better under LEDs than others.
My 5w in the reflector is 5000 fc at 9" from the diffuser, anywhere under it in a sq ft, meaning the size of the reflector itself, the upper half of the chamber. At 18" it drops to 3000, at 24" 2000, at 36"1200. However at 48" away it's down to about 500 fc. Plants need at least 1000 so I can't recommend running your 5w grow light any farther from the canopy than 36", sorry.
Lux is, by definition, a measure of light intensity per square meter. There is no such thing as "lux per square foot" You are also conflating Lux and Lumens which are totally different kinds of light measurements.
I believe you have that backwards. Higher frequency = higher energy. Longer wavelength = lower frequency, and lower energy.
Ahhh... I know what the problems here is. Meters count photons, not watt energy. More photons in a watt of low energy light, than a watt of high energy light. You are indeed correct.
Yeah, I figured it out after looking at that a little while later.
No, that's not how it works. They are calibrate to sunlight, but they still tend to focus on measuring the green part of the spectrum and then extrapolate that to a expected total amount of light if it was indeed sunlight hitting the sensor. So if there is less green light in the spectral distribution of the light source used, you will get completely incorrect measurements.
If my knob gets 6-12" inches from a 38 DD it falls over too, with a splash
Those things are looking pretty stretchy
Yeap, i agree. Like i said, Its a test of seeing what happens till i get my lights done.
Yeah it would be lumens per sq ft rather than lux, lux is not per anything, it's one lumen lighting one sq m of surface. A foot-candle is in fact 1 lumen /sq ft, hence the 10x conversion factor, a sq m being a little over 10 sq ft.
