Day 25
Today I got my new lux meter that very accurate and just as I figured… My 400w hps is completely overkill it within the ballparks of a weak 600w. At 16 inches away putting out 70 thousand lux which as many smart people would know is about as high as you want to go for flowering… At 18-20 inches it is still over 50 thousand lux.
I guess I got too much light hahah. No wonder the plants are running away from the light and some of them are folding down and to think at one point I had them up 12 inches away… Close to 80 thousand Lux. You know what this is my fault entirely since I read on the internet at 12 inches away a will only give you 53 thousand lux which is still too much light.
I really believed it now I got this lux meter that accurate within 5% I know now that a load of BS.
Mainly bought it so I can test my old equipment if they are still performing within acceptable standards and they seem to be performing over standard which is good but messing up my plants since my tent only has so much height. Could be worst I guess and the plants be light burnt.
First Application of Roots Excelurator and really good ratio at about 1mil per gallon only drama is how do you measure that out even haha so doing it by the bottle tipping it slowly counting drops… All in all good start of the week
Light Requirements of “High Energy” Plants
Amount of lux Plant Growth
1000 – 5000 lux Min. necessary for life
10000 – 15000 lux Min. necessary for consistent but sparse growth
20000 – 25000 lux Min. necessary for robust growth
25000 – 30000 lux Max. Efficiency for Sub Tropical varieties
25000 – 50000 lux Max. Efficiency for Equatorial varieties
Seems to correlate well with what I know for vegging flowers without me going into a thousand words essay. For flowering in my personnel opinion I would go by 50000 lux to 75000 lux without CO2 enrichment with you have to be providing over 70000 lux to get any kind of growth benefit at all or just wasting $$.
Activity Lux Footcandles
Direct Sunlight 32000–100000 lux 2300 - 9300 (approx) foot candles aka lumans
Daylight (not sun) 10000–25000 lux 930 - 2300 (approx) foot candles/lumans
2018 C02 right after I dial in my full hydroponic. So the plants can finally use some more light. Their is so much misinformation on the internet with trolls that pretend to grow but never grown anything in their lives and when you see anyone saying you need ten thousand PAR or footcandles he doesn’t know anything.
The plant can’t process that amount of light even with CO2 enrichment and you just going to get stressed out plant with light burns. In the end it is ultimately our own responsibility to protect our own plants by doing all the calculations ourselves and not relying on 3rd party advice since that could cost you yield/quality.
I know some of you are going to go right… I thought my plants can handle more light? I do have some findings from other people but I really do think it a bit high since I’m blasting them at 70 thousand lux right now and just by eye and you can see it in the photos I taken it about 10-20 thousand too much.
Anyways without further explanation higher estimates and ranges. Take everything with a bottle of salt
Quick Guide - Lux Levels for Optimal Cannabis Growth
Life Stage Maximum Good Minimum
Vegetative 70,000 lux 40,000 lux 15,000 lux
Flowering 85,000 lux 60,000 lux 35,000 lux
< 15,000 lux - sparse or “stretchy” growth - plant isn’t getting enough light
15,000 - 50,000 lux - good amount of light for healthy vegetative growth
45,000 - 65,000 lux - optimal amount of light for cannabis plants in the flowering (budding) stage
70,000 - 85,000 lux - a lot of light, some strains do okay at this light level, but some plants lose their top leaves early under this light intensity, especially plants that are not resistant to heat/light (like many indicas)
85,000 lux - at this light intensity, you’ve hit the plant’s “saturation point” which means your plant can’t use all the light