Technical aspects of Cannabis indoors

[Jimski]

Hello everyone. First time launching a grow and I have some questions.
Perfecting Cannabis seems to be a very technical process at the high ( hehe ) end but some previous technical training is screwing with my head. In lab work we always had to tailor our math to follow whats called " significant figures". In other words if your current measurment includes multiple variables that measure 1.012 and 1.1 than your answer has to be a single digit to the right as this " significant figure" will not allow a thousands answer as your measurement can not express a value more precise than your weakest measurment.

This is my problem. Most of the current temp and humidity sensore are plus or minus 3%. Some are as high as 7% and some manufacturers are lying their collective butts off about accuracy and precision of the instruments. Accuracy and precision are 2 different things and should not be mixed up and you need both. Precision is repeatable function accuracy is function based on established measurements.
You can have a rifle that is very precise like every bullet hole touches the other hole but with poor sights you hit the same spot 14 inches to the left, not very accurate

Case in point vpd. I have seen charts that have you adjust vpd based on leaf temp. I can not see this actually working due to temp probes that can not be base lined to match. Air temp is one type of sensor and they have to be calibrated. Touch sensors are another and infra is yet another. If your temps are not correct for actual the chart is wrong.
The second is sensor drift. Much like calibration of a ph tester you will find that syncronizing a system for inside and outside temp and humidity difficult or impossible if you use a $9 amazon gauge set. You will need a lab quality temp and humidy gauge. Using a lab gauge will get you set up but I have sent 2 systems back because the sensor drift after calibration will not last a week. If your humidy and temps drift your vpd means squat.
Basically I can not see any of the grow tent systems being able to adjust for all these problems and them selling this as a system just seems to be false.
Not giving up on tent grows but the controllers will be in manual mode and i have lab grade manual temp and humidity for both in and out and will just do the math. Just wish I had not gotten the kits with the preset grow number controllers and wasted my time.
Now the big question. Overthinking this stuff? Pot is easy to grow? Very forgiving? I can follow a plan and the mental exercise had been enjoyable but if I spend 2 months gathering data and building a grow to produce caca I will be kinda pissed.....

 

[Phytoplankton]

Pot is easy to grow, and it’s fairly forgiving. Don’t overthink it. Pot grows in a wide range of conditions in the wild, none are perfect, it grows just fine. You can spend a bundle and get all the rh, ph, temp, heat, light, measuring instruments and use them to create a “perfect” environment, but there is a point of diminishing return.

 

[Jimski]

I guess I am just pissed that the " systems" that automate the conditions is not true. I really believe selling these as a system with the provided sensors is a fraud. You can set your grids and temps all you want but with wrong data your chasing problems.
l

 

[Delps8]

Hello everyone. First time launching a grow and I have some questions.
Perfecting Cannabis seems to be a very technical process at the high ( hehe ) end but some previous technical training is screwing with my head. In lab work we always had to tailor our math to follow whats called " significant figures". In other words if your current measurment includes multiple variables that measure 1.012 and 1.1 than your answer has to be a single digit to the right as this " significant figure" will not allow a thousands answer as your measurement can not express a value more precise than your weakest measurment.

This is my problem. Most of the current temp and humidity sensore are plus or minus 3%. Some are as high as 7% and some manufacturers are lying their collective butts off about accuracy and precision of the instruments. Accuracy and precision are 2 different things and should not be mixed up and you need both. Precision is repeatable function accuracy is function based on established measurements.
You can have a rifle that is very precise like every bullet hole touches the other hole but with poor sights you hit the same spot 14 inches to the left, not very accurate

Case in point vpd. I have seen charts that have you adjust vpd based on leaf temp. I can not see this actually working due to temp probes that can not be base lined to match. Air temp is one type of sensor and they have to be calibrated. Touch sensors are another and infra is yet another. If your temps are not correct for actual the chart is wrong.
The second is sensor drift. Much like calibration of a ph tester you will find that syncronizing a system for inside and outside temp and humidity difficult or impossible if you use a $9 amazon gauge set. You will need a lab quality temp and humidy gauge. Using a lab gauge will get you set up but I have sent 2 systems back because the sensor drift after calibration will not last a week. If your humidy and temps drift your vpd means squat.
Basically I can not see any of the grow tent systems being able to adjust for all these problems and them selling this as a system just seems to be false.
Not giving up on tent grows but the controllers will be in manual mode and i have lab grade manual temp and humidity for both in and out and will just do the math. Just wish I had not gotten the kits with the preset grow number controllers and wasted my time.
Now the big question. Overthinking this stuff? Pot is easy to grow? Very forgiving? I can follow a plan and the mental exercise had been enjoyable but if I spend 2 months gathering data and building a grow to produce caca I will be kinda pissed.....

You're doing what you do because that behavior and perspective is why you are where you are in life and your career. It's only natural that will bring that perspective into growing cannabis.

It's a plant. <===== repeat 5 times.

Yes, the meters that we use have larger inaccuracies than laboratory equipment because those inaccuracies are acceptable for agriculture.

It's a plant.

The environment in a grow tent is chaotic because…it's a plant.

I'm on my third generation of sensors and controllers and have gone so far as to put sensors in the plant and it's really quite something to see the different values for temperature and RH in different places in the tent and in different locations under the canopy.

That's just the way it is because the plant is a living organism that is constantly interacting with the environment.

I can go into specifics for each to the parameters of growth (I've gone so far as to buy an anemometer so I can set windspeed in the tent to 2 meters/second) but, overall, if you can "keep it between the guardrails", everything will turn out fine.

The big driver <climbs up on soapbox> is that, by and large, growers do not give their plants enough light and they end up with modest yields. Since you're comfortable with meters, get a lux meter ($32 for a Uni-T at Amazon) and get your plants to their light saturation point as soon as possible (the PPFD for LSP changes through seedling and veg and early flower) and you will end up with a huge amount of cannabis.

Hope that helps. I was a "helicopter plant daddy" for my first few grows. Everything will work out fine because…

 

[OldMedUser]

↑ ↑ ↑ That right there!

I brought my science training, chemistry, into the grow room for a while too but had had plenty good enough grows for many years before that training.

Helped to dial some things in but overall didn't make a huge difference.

 

[OldMedUser]

I guess I am just pissed that the " systems" that automate the conditions is not true. I really believe selling these as a system with the provided sensors is a fraud. You can set your grids and temps all you want but with wrong data your chasing problems.
l

Most of that shit is to reel in new growers and score some of their cash.

Seems to work.

I got a lot of money invested wasted on stuff I never really used and going to be flogging it online since grows are legal here in Canukistan. $400 in CO2 controller and it's regulator etc when a freakin candle in the grow room can get my CO2 over 1500ppm. Another $170 for a 600cfm carbon filter still sealed up and good as new. $125 for an 8" inline fan for a grow project I'll never build. The list goes on.

I haven't even had a plant growing for the last year and any future grows will be modest ones so have way more lights than I need and a Light Rail unit I paid $400 for and used for 3 flower cycles I could maybe get $150 for. All my lights are HID so barely worth trying to sell unless it's local as it would cost more to ship than they're worth. I live way up in north in Bumf**k Alberta so not a huge local market but ya never know.

KISS, (Keep It Simple Stoner) is the way to roll IMO. It's just a plant, not a magic plant.

 

[ProPheT 216]

Op. If you have never grown before your over thinking. You will run into plenty of issues before your questions even matter. Get a good light, move air, learn to feed properly.

 

[Jimski]

You're doing what you do because that behavior and perspective is why you are where you are in life and your career. It's only natural that will bring that perspective into growing cannabis.

It's a plant. <===== repeat 5 times.

Yes, the meters that we use have larger inaccuracies than laboratory equipment because those inaccuracies are acceptable for agriculture.

It's a plant.

The environment in a grow tent is chaotic because…it's a plant.

I'm on my third generation of sensors and controllers and have gone so far as to put sensors in the plant and it's really quite something to see the different values for temperature and RH in different places in the tent and in different locations under the canopy.

That's just the way it is because the plant is a living organism that is constantly interacting with the environment.

I can go into specifics for each to the parameters of growth (I've gone so far as to buy an anemometer so I can set windspeed in the tent to 2 meters/second) but, overall, if you can "keep it between the guardrails", everything will turn out fine.

The big driver <climbs up on soapbox> is that, by and large, growers do not give their plants enough light and they end up with modest yields. Since you're comfortable with meters, get a lux meter ($32 for a Uni-T at Amazon) and get your plants to their light saturation point as soon as possible (the PPFD for LSP changes through seedling and veg and early flower) and you will end up with a huge amount of cannabis.

Hope that helps. I was a "helicopter plant daddy" for my first few grows. Everything will work out fine because…

Thanks for the reply. I am actually planning to " fail " as my first 3x3 will be with only 150 watts. I know the yield will suffer but I want to gain some experiance with modest grow before trying to crank out lots of buds. From reading ummmm EVERYTHING the last 3 weeks the more you push the more you need the experiance of what plants do and why. Read about more than a few guys tapping out after a string of bad grows. I got no choice. The local MMP is so high ( hehe ) priced for basically 3 months of cannabis cost I got a 2 bucket dws and a tent. Super great lung room basement huge 68 degrees and a rh of 65 and with a built in hvac can lower to 40 in steps like a few reads stated.

I actually have a lot of experiance with outdoor grows but mine is all vegetables. In veggies there are goals that everyone has who does it for very long and I have several.
3 sisters Native American Planting 1 acre.
15 foot tall fence of mortgage lifter tomatoes.
Popcorn including drying and packaging.
Forever strawberries.( runner clones )

You're doing what you do because that behavior and perspective is why you are where you are in life and your career. It's only natural that will bring that perspective into growing cannabis.

It's a plant. <===== repeat 5 times


Message recieved.
I do have experience growing stuff but its all vegetables outside. I have a few acres and a pond and have done large gardens and even an acre of popcorn and an acre of 3 Sisters Native American planting.

I have a lot of things going for me with my setup. It seems that a lot of humidity and temp issues are due to lung rooms. I have a huge basement stable at 67f and 60rh. I can lower RH to 40 in steps with hvac controls. 3x3 tent with 2 plants and only 150 watts will not yield a lot but looking to learn and I have a huge issue with my tent that needs testing. Using pulleys and 4mm para I have a hand crank that will raise and lower the dwc baskets with scrog assembly connected. Due to a screwed up back I have no choice but to get this right. I can not reach and lift much more than a dozen lbs. Will try with what I assume will be smaller plants with less mass. If the counterbalance system is a fail and it dumps the lot of it I will be pissed. The math to decide spring tension was great fun if it works and a &####!!/xxxx waste of time if it does not.

 

[ProPheT 216]

Thanks for the reply. I am actually planning to " fail " as my first 3x3 will be with only 150 watts. I know the yield will suffer but I want to gain some experiance with modest grow before trying to crank out lots of buds. From reading ummmm EVERYTHING the last 3 weeks the more you push the more you need the experiance of what plants do and why. Read about more than a few guys tapping out after a string of bad grows. I got no choice. The local MMP is so high ( hehe ) priced for basically 3 months of cannabis cost I got a 2 bucket dws and a tent. Super great lung room basement huge 68 degrees and a rh of 65 and with a built in hvac can lower to 40 in steps like a few reads stated.

I actually have a lot of experiance with outdoor grows but mine is all vegetables. In veggies there are goals that everyone has who does it for very long and I have several.
3 sisters Native American Planting 1 acre.
15 foot tall fence of mortgage lifter tomatoes.
Popcorn including drying and packaging.
Forever strawberries.( runner clones )

Hopefully you won't fail. But each plant will use about 175-220 watts effectively without CO2. Your def a lil underpowered for multiple plants but a good learning run. Be happy help along the way