Lighting Light intensity for autoflowering plants (lux)?

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So I am getting ready my setup for my first indoor grow (I have completed several outdoor grows so far, so not a total noob), and I have been wondering about the recommended light intensity in the different stages for autoflowering plants. As I want to be as precise as possible I will be using a lux meter to have some basic form of measurement. I will be growing autoflowering only plants (Mephisto seeds). I have found online some information about light intensity here https://www.growweedeasy.com/lux-meter , mainly 40,000 lux for vegetative and 60,000 lux for flowering but it pertains to photoperiod plants with 18-6 vegetative and 12-12 flowering schedule. What light intensity would you recommend for vegetative & flowering for 20-4 and 24-0 schedules respectively?
 
Are you running DIY lights because that information about most commercial light fixtures is out there already? What light will you be running?

LUX ≠ PAR so you do not get an apples to apples picture. DLI is the measure of PAR light a plant gets/needs in a day. There are some converters that will get you somewhere in the ball park.

http://pllight.com/demystifying-light-levels-for-cannabis-grows/

:vibe:
 
I will be using LED lighting (Mars Hydro SP-3000). I am aware that LUX is not the correct unit of measurement however a getting a PAR meter atm is totally out of my budget. A lux meter will hopefully give me some kind of measurement that will be more accurate than just me eyeballing it. How do you measure the light intensity in your grows? Just by experience and the instructions given by the manufacturer?
 
According to How Much Light (PPF) Do You Need for Indoor Cannabis? - Coco For Cannabis
cannabis prefers a PPFD (Photosynthetic Photon Flux Density) of 500-700 (using the appropriate units).
From Convert Lux to PPFD - Online Calculator | Waveform Lighting
for a 2000 K HPS light, 60,000 Lux corresponds to a PPFD of 778, which is slightly more than the 700 maximum.

The widespread use of powerful LEDs has created a new health problem for growers, too much light.
Especially if LED users go by the Lux values that HPS growers do.
A Lux of 60,000 from a 3500 K Rspec LED corresponds to a PPFD of 5,324 which is way too much.
For an Rspec LED, to get a maximum PPFD of 700 needs only 27,000 Lux.
This matches my experience of getting light burn beyond 30,000 Lux.
My autos seem happiest at around 20,000 Lux, which corresponds to the minimum PPFD needed.
But autos do get more light than photos, which gives a greater risk of burn.
 
According to How Much Light (PPF) Do You Need for Indoor Cannabis? - Coco For Cannabis
cannabis prefers a PPFD (Photosynthetic Photon Flux Density) of 500-700 (using the appropriate units).
From Convert Lux to PPFD - Online Calculator | Waveform Lighting
for a 2000 K HPS light, 60,000 Lux corresponds to a PPFD of 778, which is slightly more than the 700 maximum.

The widespread use of powerful LEDs has created a new health problem for growers, too much light.
Especially if LED users go by the Lux values that HPS growers do.
A Lux of 60,000 from a 3500 K Rspec LED corresponds to a PPFD of 5,324 which is way too much.
For an Rspec LED, to get a maximum PPFD of 700 needs only 27,000 Lux.
This matches my experience of getting light burn beyond 30,000 Lux.
My autos seem happiest at around 20,000 Lux, which corresponds to the minimum PPFD needed.
But autos do get more light than photos, which gives a greater risk of burn.

I see. That makes total sense. I guess I will start with 20.000 lux during flowering and take it from there. As I will be growing autos, that was what I was thinking, more light hours less intensity needed.
 
For around $30 a Dr.meter LX1330B lux meter might work...
 
HOW MUCH LIGHT DO YOUR CANNABIS PLANTS REQUIRE?

  • Clones and seedlings: 5,000–7,000 lux
  • Vegetative growth: 15,000–50,000 lux
  • Flowering: 45,000–65,000 lux
  • Maximum recommended amount of light: 75,000 lux
I use the UNI-T UT383 and get 2.25 grams/W with a QB288 v2 Rspec 3000k running at 90W in a 2x2.
 
I have rented a PAR meter from here several times when building lights.

Conversion lux to PAR in case of LED lamp it is very difficult, especially in those lamps which have different light spectra. The crucial difference between lux and PAR is that lux-meters determining lumen value for a lamp is based on the sensitivity of the human eye, with yellow-green wavelengths given the highest weighting. (lux = lumen per m2) Due to this for LED lamps with different spectra is really hard to convert/estimate PAR value from lux measurments. Of course if someone performed such conversion co-factor for blue, red and white's LED you have to remember that this conversion co-factor should be calculated for the same wave lengths which were emited by blue, red LED lamp investigated by you

The conversion is possible if the emission spectrum of the source is know. If the spectrum is constant (no mixing with sunlight, no-computer control of individual colour channels) and possibly no-dimming, then a conversion factor can be obtained by taking repeated measurements with a spectrometer and your lux-meter side-by-side and comparing the measurements.
The problem also exists to a larger or smaller degree also with most PAR sensors. Few broadband sensors have the exact expected spectral response, and need to be calibrated as described above to obtain precise readings with any light source different to that used for the original calibration. Depending on the brand and type of PAR sensor, and how discontinuous (ragged) the spectrum from the light source is, errors in the measurements can be over 30% even when using PAR sensors.
As a side note: one of the most frequent sources of errors in light measurements is shading by the operator, or possibly reflection if operators wear a white lab coat. Spatial variation tends to be also high in greenhouses, so replicates in space (and time) are always needed.

I will be using LED lighting (Mars Hydro SP-3000). I am aware that LUX is not the correct unit of measurement however a getting a PAR meter atm is totally out of my budget. A lux meter will hopefully give me some kind of measurement that will be more accurate than just me eyeballing it. How do you measure the light intensity in your grows? Just by experience and the instructions given by the manufacturer?
 
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