Minimum 18/6 autoflower dli

Can anyone tell me the minimum dli for an autoflower in flower on 18/6 is it 32? I have it at about 900 ppfd 18 hours a day is that enough or too much

From what I have read :

Cannabis grow window with natural CO2 environment is between 20 and 40 moles.

At 40 moles (max) 18hrs a day would be 617ppfd.

40moles / day :
40,000,000 ÷ # lights on hours ÷ 60 ÷ 60 =
umols required.

Personally had been using 15 hrs lights on requiring 740 ppfd.

Really I had been reading you can push your plants to 600 at minimum and 900 highest without c02 1500 maybe ive been using too much ligjt

I've also read that you only require additional c02 if you go over 1000ppfd
However that doesn't mean that having them on 900ppfd is beneficial
Different stages of growth + different grow environments = different ppfd needs

During flower a photo period plant is usually run at 12 hrs a day. Using the formula at 40 moles would require 925. If that was dropped to 11hrs lights on then would require 1010.
During veg, usually 18 hrs of light per day, at 40 moles would require 617.

Perhaps the 600-900 you were referring to is: 600 at 18 hrs for veg (or full cycle for an auto), and 900 at 12 hrs for flower. Those would be approximate max usable light with normal co2 conditions assuming all other environmental aspects are dialed in.

Have also read where around 1000 is the max a plant can effectively use without co2. That leads me to believe that 11 hrs during flower with lights at 1000 is as efficient as can be expected from a flowering cannabis plant without co2 supplementation provided the environment is dialed in.

Patriots781 said:

Really I had been reading you can push your plants to 600 at minimum and 900 highest without c02 1500 maybe ive been using too much ligjt

Click to expand...

You can do it, but there is diminishing returns. The jump from say 750 to 1000ppfd is not as beneficial as the jump from 500 to 750 ppfd