I had a terrible year for tomatoes. The heirloom Cherokees were ruined by rain, the San marzanos all had blossom end rot, and I think I got 3 Wisconsin’s successfully.
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Well, 48 hours later and they have all popped.
The tent has been behaving well. Ambient 90 degree days with lights on and I easily stayed at 80 degrees. Wasnt worried about variances while germinating so it gave me a chance to dial things in better. On average the AC was turning for 3 minutes once every 20 minutes. We will see what that does to the Duke Power bill.
In a few days I will cull the weakest two, then stick the rest in the buckets.
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Slowly dialing the tent in, going well.
The red circles are operator error, I didnt seat the humidifier reservoir properly and it didnt feed.
Will rinse the clay pebble media tonight and embed the rockwool cubes in the pots tomorrow.
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Im gonna follow along… It has been a while since I have seen a hydro grow. I forgot how much work it is to get everything setup. Looks like you got some fun toys too.
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Tent is cooperating well. Stuck 4 seedlings in their new homes. A little early LST to try to make enough elbow room. I didnt read anywhere that these were Fems so I am allowing that I may need to cull 1 or more later on down the line.
I only hooked up 1 air pump and 1 airstone per vessel. I suspect my design would be over aerating with out additional benefit… I picked up a dissolved O2 titration kit so that I can measure it. Once the sump stabilizes after just being filled I will take measurements (in the grow buckets) with different amounts of aeration to see just ho much aeration I need to maximize dissolve O2.
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OK, enough LST for now. Now I just LITFA and let them grow for awhile.
Start to finish of seedling LST:
So, I have been thinking, if I do wind up with a mixed bag of sexes, whats the probability of success if I were to just let them flower together, given the crowded nature of the tent. Would a natural pollination have a good shot?
This is what I know about the strain:
The only other reference I could find is this:
https://www.linda-seeds.com/en/buy-autoflowering-marijuana-seeds/hybrid/high-content-of-thc/large-yield/auto-northern-light-linda-seeds
@Carty any other insight?
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Looking back at the environmental controls over the first full week:
Temp:
Started with a setpoint of 82 F, reduced by 1 degree each day until I got to 78F and left it there. Temp is holding pretty good. I was able to reduce the hysteresis swing by 50% by the end of the week. Look at the yellow circles, the amplitude of the swings (on/off cycles) was cut in half.
Humidity:
I feel confident I can improve stability here.Reduced the hysteresis swing by 50% (yellow circles). Still need some work to improve it. I do not have any active de-humidification yet. Dont need it much yet except during lights out (Blue lines). I have purchased 2 large dehumidifiers for the tent, both wound up inside the house as the house needed it. Waiting until I absolutely need it before I snatch one out of the house. When I do the humidity will be much more stable. The red circle was an error where I didnt seat the tank properly.
I noticed a phenomena where every time the AC cut on, the humidity would drop drastically. This led to huge swings in humidity. So I added a second humidifier that runs wide open any time the AC is one, and I let the other humidifier stay controlled by the Inkbird. This change happened at the White Arrow above. It has definitely helped.
VPD:
Reduced the hysteresis swing by 50% (yellow circles). Bottom line is once I stabilize the humidity, the VPD will stabilize as well.
Sump is running at 72f with active evaporative cooling. Would like to reduce it to 68f. As ambient temps drop I am hoping I will easily achieve the 68. Rez is loaded at 6.1ph at 300ppm. The roots have not reached the pool yet, but will in a day or two. I drizzle a little rez water near the rockwool cubes once a day until the roots reach the pool.
I am running the lights at 30 DLI. 20 hours on and 4 off. Trying to push them a bit to make the most of the “Auto” time cycle.
Input, suggestions, wild ass ideas, are all welcome!
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I appreciate the data and analysis Mr. Wiz. It’s challenging to get a room/lab under climate control and you are getting it dialed in. I’d follow this just for that story!
Did I see an Optimus wet steam humidifier in one of your pics? I like those and think it will serve well in our desiccated Northeast winters.
My only suggestion is that “30 DLI” is nudging the “sunburn” zone for most strains. Modern LEDs are some strong mojo. 
Respect,
-Grouchy
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You are right, dropped it to 19 DLI.
Yes, I bought the Optimus a few weeks back based on your recommendation. I like it so far.
Cheers,
M
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LIFTA time…
Look how pretty the Tent temp is.
Current targets of improvement:
Humidity control: The control band is too wide, getting setpoint +/- 8%, too crude. Need to get down to +/- 5% or less.
Notice the yellow circles, after I added a dehumidifier yesterday, I am getting a more stable median avg, however the amplitude of the on/off cycles almost doubled and the frequency of correction decreased. (more time between peaks).
Going to just keep dialing it in now that I added active de-humidification. I feel like I am getting there. Look at all the trends after 9/5 (right side of red line), much more stable.
The 50 pint dehumidifier is too large to fit in the tent so I hacked to to make it external.
Bought one of these: https://www.amazon.com/dp/B01EY1NCM8?psc=1&ref=ppx_yo2ov_dt_b_product_details
Attached it with 2 screws over the output vent of the de-humidifier. Hooked up a 4" dryer duct and a duct booster to direct it into the tent.
Reducing Rez temps: Waiting for ambient temps to drop, they are going down everyday. I do have a bathroom exhaust fan mounted in the lid of the cooler providing evaporative cooling whenever sump is above 68F.
It buys me 4-5 degrees of cooling. This is the best I can do without a water chiller, not ready for that expense yet if I can avoid it.
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everybody seems to be putting pictures on here this is one of my favorites i live on a lake here in TEXAS and fish every day 
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I’m gonna need to hire you for my next growroom build… pair you up with Reiko and I’ll man the bar and grill.
Seriously, outstanding work on dialing in your environment!
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Day 8:
Now that temps are getting into the low 80s outside, the tent is responding a lot better. The AC I use really plunges the humidity, being able to turn the AC off will help stabilize things even more.
Roots have started touching the nutrient pool, I expect growth to start picking up.
Now, I am going to apply copious dosses of this:
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You do good work Mr. Wiz! Love the DIY mods and slick automation.
I noticed that the VPD value in your photo, 0.63 kPa, is spot on for your baby plants. I tend to obsess on VPD and it’s nice to see that you have it dialed in.
The humidity here in New England is dropping as Fall approaches and I’ll need to break out the humidifier sometime soon. My plants seem to love the warm steam during the winter.
Best wishes on a great grow!
-Grouchy
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Yeah, the VPD concept made perfect sense to me the first time I saw it. VPD is my driver, I might adjust temp or humidity (usually humidity) to achieve it, but I do focus on it as my main variable.
And now… DLI has taken a more prominent place in my priority hierarchy. As you suggested, the DLI was too high to begin with and the 1st 2 sets of leaves got burnt tips. Lowered it down to 15 and am now following the chart closely. Raising about 1 DLI per day.
Still real curious about long/short days within the same DLI spec. From an energy perspective I suspect you are right, it is probably close to a wash. However what about from a growth perspective? Could longer, but somewhat dimmer days give more growth than shorter brighter days. Could the brighter days lead to less stretch? DLI leaves a considerable range of variability, and surely that variability can be harnessed to some advantage. This begs for a controlled study.
Environmental controls: Tweaking this in closer has been an exercise in physics. The AC allowed me to run in this heat otherwise the yellow circles would have been off the charts. But, that AC is a double edge sword, the instant it cuts on it drops the humidity through the bottom, and a lot faster than the temp drops. Add 2 different humidifiers to offset the AC humidity drop. Add a dehumidifier that also adds heat. Trying balance it all has been fun.
Finally today I think I nailed my sweet spot for dial settings, as seen to the right of the red line.
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This is super outrageous. Very cool, brother. I’m starting to realize that we have very different growing styles. Keep up the good work.
I’m sure you’ve already said, but what is that program you’re running to chart all of your inputs?
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Growing weed is akin to spirituality.
There are many paths to the top of the mountain…
The view from the top is still pretty awesome regardless!
@Indicana_Jones I do not know your grow style, but I can certainly validate that it works well as your results speak for themselves. -----> Respect!
In fact I am curious about a few things, like your trim job. Wondering how you accomplish it.
My style is largely a result of my profession. I spent most of my career in the Industrial Instrumentation & Controls sector as an I&C Engineer. We used a variety of instruments and controls to calibrate, monitor, and control pH, flow, level, temp, humidity, dew point, speed, pressure, force, O2, vibration, color, and other physical attributes. This discipline heavily relies on hard data.
I take this approach to my grows. I look at all the variables that I can identify, and then break those variables down into individual control loops, which I then tune to get the best result. I rely on hard data and charts to guide me as to what setpoints to target. I read copiously in multiple sciences and industries (& here on OG) and take what I can from each one. Borrowing heavily from data and processes that have been validated beyond the anecdotal.
I started out with cheaper Inkbird controllers and common household appliances.
I see myself eventually converting the on/off Inkbird control loops to PID controlled analogue endpoints. Inkbirds are crude control at best. PID controls can be configured/tuned to be much much more precise.
What follows is what I am currently using in terms of standards and resources.
For control I use wifi enabled Inkbirds to control the following:
- Heater
- A/C
- Humidifiers
- DeHumidifier
- Rez evaporative cooling
- Rez aquarium heater
Additionally I use:
- An AC Infinity controller and duct fan used mostly for overtemp situations.
- pH, ppm, are monitored with a Bluelabs Guardian. No wifi
- The Photone app on my cellphone to measure ppfd and DLI
@Indicana_Jones I wasnt sure if you were asking about the temp/humid charts or the Functional Diagram in the 1st post…
For the Functional Diagram I use a program called SmartDraw: https://www.smartdraw.com/
To “monitor” I use a handful of wifi “SensorPush” sensors. https://www.sensorpush.com/
These are highly accurate, much more so than the Inkbirds. They allow for solid datalogging and charting. I use them to monitor the Tent and my curing process.
Below are the resources I adopted after sorting through many variations of them. If you have a better resource please bring it to my attention.
VPD
DLI
pH
I let it drift between 5.5 and 6.2
PPM
Troubleshooting
When in doubt:
Edited to add:
I have only been back at this for a year. I dont claim anything I am doing is any better than anything someone else is doing, I am simply finding my way, the best way I know how…
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As a Fellow SyE in a different industry, I find your data fascinating… I have something similar to what you have but just does temp/humidity w/ alarms… Time to up my game.
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These are the Data-points I check at least daily, if not more…
Looks the pH needs to come down a little. Also going to bump up the ppm to 500. The nutes will probably lower the pH enough without having to adjust further.
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For trimming I pulled all large fan leaves before drying. Once dry I cut the plant into single branches and do a pretty tight hand trim on all of the remaining leaves that were buried too tight to pluck. As each bud is trimmed it gets snipped from the stem and into a bucket. I think it took about 8 hours to hand trim a pound. I don’t think I physically touch the buds at all unless they need to be bent away from the main stem while trimming. Any little scraps of leaves left dry out and crumble away during the curing process.
We talked a little bit about how my grow went but I really do treat these plants like shit. Sometimes on purpose and sometimes on accident. I like to think of my style as nature and your style as nurture.
I’m pretty sure I spit on one of my underperformers right before I chopped it down, just to set precedence for the other plants watching.
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