Back in a bit, got lots of ideas & need to read the thread more...
Back in a bit, got lots of ideas & need to read the thread more...
B1unt XIII: Chemdogging & Sour Diesel - https://www.thctalk.com/cannabis-for...post1071304159
barney_b (19-02-22), Doink (19-02-22), DomoArigato (19-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), Mac (19-02-22), scoot (19-02-22)
Drooping before the lights go out could be caused by feeding a low EC to the point where they don't have the nutrients to keep photosynthesizing, so they clock out early (or they're being given too much light for the EC).
The plants don't necessarily show deficiencies as the plants feed while they're photosynthesizing.
Is a rest good for Auto's: Probably, science says it stops the roots producing exudates & seems more focused on the rest the microbial life get (no mention of synthetic grown plants).
Is it needed?: No (& you may well have a better grow from a more stable environment).
Last edited by B1unt; 19-02-22 at 12:45 PM.
barney_b (19-02-22), Doink (19-02-22), DomoArigato (19-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Mac (19-02-22), scoot (19-02-22)
Where did you get 40 DLI from?
I can't remember how but I calculated a DLI of 37 in flower for an atmospheric Co2 level of 400ppm? (& then I rounded it down to 35, assuming I am not hitting everything (environment, feed etc) 100% so not running the max amount of light).
Also it looks like DLI should fluctuate through the run ...
You'd have to perform test runs & work this out; same strain run one at 35DLI & another at 40 (not very scientific but if you don't notice a difference then 35DLI it is )
See below*
The DLI vs. Co2 topic is really; DLI vs. Co2 vs.EC..
As the Co2 level is increased, the DLI is increased & the EC also be raised.
Increasing Co2 increases growth. Which requires increased light levels & temperature to optimize (as well as a higher EC but there's no scale for that)...
What? Oxygen's the plants "waste" product (Unless it's in the rhizosphere = AutoPot AirDomes )
Humidity / VPD (optimum environmental parameters)
I think the atmospheric Co2 level (400ppm) is going to determine the DLI.
Lights can be cranked up to a higher DLI & you can push the EC up, but unless you're adding supplemental Co2 it will always be thing limiting factor (the thing you run of of first).
That's not a very good flex if your environment, feeding & co2 aren't dialed in to suit
*Transpiration / growth increases with temperature (to a point)...
After spinning out looking at VPD charts I came to the conclusion that it covers a 10° range (20°-30°c)...?
Turns out there's are optimum range which is leaf surface temperature of 26°c (which would require an RH of 57% in flower).
So if your ambient temp is 24°c & your leaf surface temp is 20°c & you struggle to keep RH below 60%, I'd imagine you'd take a hit from our "100%" (compared to 27°c leaf surface temperature & 57% RH).
Obviously if you're nailing VPD, increasing Co2 & matching the DLI & EC away you go
Conclusion:
If you want to 100% nail your grow (based on an atmospheric Co2 level of 400ppm), you (probably ) want something like...
Co2 - 400pm static.
Light - DLI calculated by stage of growth / Co2 Level.
Temperature - Leaf surface temp: 26°c.
- Ambient Temp: 30°c.
- Night time temps want maintaining too for a 100% run.
VPD - Match the ambient RH level to leaf surface temperature.
EC - High enough to match the DLI level (provided our VPD is dialed in & the plants are transpiring photosynthesizing at 100%).
This is just my theory, but if you nail all of those 100% (as well as airflow, feeding etc), you'll get 100% return on the DLI & Co2.
Assuming we're not nailing all those things, we're probably hitting closer to like 75%.This could well indicate our calculated DLI is possibly 25% higher than necessary
I can't find a good source for the "DLI vs. Co2 vs. EC" conversation as it's probably too strain specific.
However it's important to note that not feeding enough would quickly become a limiting factor, if it was less than the required amount to support photosynthesis @ a Co2 level of 400ppm (in theory everyone has too much light so that's probably not an issue ).
Last edited by B1unt; 19-02-22 at 02:54 PM.
barney_b (19-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (19-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Jstatus (19-02-22), Mac (19-02-22), mpsj (19-02-22), Samwise Gamgee (02-03-22), scoot (19-02-22)
Wow. Going to need at least as much time as it took to put that together to absorb and respond. Hell of a write-up B1unt! This will be bookmarked for future conversations.
Cheers
Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (19-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Jstatus (19-02-22), Mac (19-02-22), scoot (19-02-22)
Lots of interesting data. For what it's worth, the PPFD Meter I'm using says 10-40 DLI is the ideal range. The meter reads DLI with category readings either LOW, GOOD, HIGH and MAX. When the reading reaches 20 DLI it goes from LOW to GOOD.
barney_b (21-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Jstatus (19-02-22), Mac (21-02-22), scoot (19-02-22)
B1unt is in the house.
What a Response of magnitude.
Fair play to you mate and thank you for taking the time.
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B1unt (19-02-22), barney_b (21-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Mac (21-02-22), scoot (19-02-22)
Agreed, a fantastic post B1unt, cheers for sharing
B1unt (19-02-22), barney_b (21-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), Jstatus (19-02-22), Mac (21-02-22), scoot (19-02-22)
The shit thing is that you need the proper gear to measure the VPD and DLI correctly.
And I'm sure this Photone app I'm using is not adequate enough. Lol
I know now that "More is Less" and "Less is More" and I need better equipment!
It's good to get a better understanding before I spend out anymore.
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B1unt (19-02-22), barney_b (21-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Mac (21-02-22), scoot (19-02-22)
B1unt (19-02-22), barney_b (21-02-22), Blue61 (19-02-22), Deku Nut (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), IceCalibur (19-02-22), Jstatus (19-02-22), Mac (21-02-22), scoot (19-02-22)
VPD is a simple calculation from the Phonetone app.
To work out your VPD take an infrared thermometer, measure the leaf surface temperature & reference the chart to see what the RH should be..
Better than guessing, it measures consistently, just make sure to take multiple measurements at canopy height & average them.
People tend to believe pumping the plant with too much light & nutrients does't make the plant grow faster / bigger /better.
But we still do it anyway
The question is are you an obsessive compulsive weirdo or not
barney_b (21-02-22), Deku Nut (19-02-22), Doink (19-02-22), DomoArigato (20-02-22), Farmer Geddon (20-02-22), GEORGE (19-02-22), Jstatus (19-02-22), Mac (21-02-22), scoot (19-02-22)
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