Critical Purple Kush - VPD FTW

Not much going on yet. Added some 3d printed supports to make sure they don't start flopping over. Not sure if it's the strain, or my idiocy, but these bastards are soooo leggy. Grr. Watering daily to 15% runoff with MegaCrop 2 part in RO at 0.6EC and 5.6pH. Found Mega Crop gives very stable pH on the right range without any pH up or down needed. Took one day off (3/18) watering to water with Silica Boost at 6ml/gal concentration pHed to 5.4. PPFD 300 at canopy for DLI of 20. PPFD was about 20 for first week while I was prepping and sanitizing the grow room, which might explain the leggyness. If they don't look better after topping, I might pull them and try a different strain. 3/20 - this grow is inspired by the techniques of Bruce Bugbee (PPFD, nutrition, EC monitoring, substrate, environment, etc) and the concept of VPD control, both of which served me very well in the past. The grow room has dual PID controls in my PLC regulating the temperature and humidity to lock in the VPD based on plant age. In later veg and flower, I had CO2 injection on a PID, but that ultimately failed because I couldn't get the humidity down as it got huge. Had too many vent cycles. This year, hope to source or kludge an in-line dehumidifier so I can keep the sealed chamber where it needs to be without wasting CO2. 3/22 no more vertical growth, thank god, leaves and roots are slowly catching up. Patience. EC to 0.7

Topped 3/26. Yeah, they're young, but they can take it. Gotta move things along. 3/29 - so, not much growth yet, so let me explain my nutrient tank. I have a 5 gal bucket with low level and high level float switches, a fill solenoid, a large circulation pump, and a smaller feed pump. There are also 3 solenoids in the feed loop. 1 solenoid opens a return path the the reservoir so the feed line flushes for about 20 seconds. Then, the recirc solenoid closes, and each if the 2 feed solenoids open in sequence, for a set period of time that varies by the plant age and the planter size I'm using. When the low level triggers, the fill solenoid activates to refill the reservoir until the high level trips. During the refill process, I have 4 dosing pumps adding different fertilizer concentrates to the reservoir based on my target EC and N-P-K-Ca-Mg-S ratio. Piece of cake! 3/30 - fan leaves getting bigger. PPFD to 400. 4/1 - PPFD to 500 Boiled coco/perlite medium and grow bags. I'll give em a good soak with 0.7EC tomorrow, check leachate ph, and probably transplant Sunday.

Just getting started on the right foot. Coco and bags sterilized and flushed thoroughly with 0.7EC at 6.0pH solution. Will transplant tomorrow once the coco drains down a bit. Plants look great and excited to push down the accelerator. 4/2 - transplanted into 3 gal and watered in. 4/4 - Reservoir cleaned, sanitized, and online. Switched to tap water (0.3EC) and nutes at 0.8EC for total of 1.1. Ph 5.9. New feed pump installed (no more getting electrocuted when I put my hand in the bucket. YAY!) and 5" watering rings installed. PPFD 550. 4/5 - really quite chuffed. PPFD to 600 and they are looking great. Moved Zoey up 2" to match canopy height. 4/6 - switched Silica Boost to foliar spray at rate of 40ml / gal in RO water, pH to 5.8

4/8 - They are doing great. PPFD at 800. Debating if I want to do CO2 this grow, because I could easily get 1000 PPFD out of this light. That means adding a dehumidifier to keep a sealed environment, but don't think there's enough of a cost benefit. Might just add more far red at lights on and lights off to try and get a little more vegetative stretch before I switch over to 12/12. Clock is ticking. Mother-in-law shows up 6/15, and I'll want it chopped by then. 4/8 - on further calculation, I'm switching to flower today. Never switched this early before, but we'll see how it goes, eh? 4/9 - prepping for vacation. Bought new 10 gal Roughneck storage container, mixed new nute mix 2:1:2. EC 1.40 with 0.3 tap water. 11ml of pH down to get PH from 6.4 to 5.8. Ditching the auto fill. Too high risk for flooding without flare fittings. Don't trust cheap-ass quick connect push fittings. 4/10 - turned off "seedling vpd mode" which kept humidity artificially high. Turned on 2nd bank of LED lights, so system is pulling about 370W with lights on, still significantly dimmed down. Turned on light cooling circ fan, which is a sealed aluminum labyrinth tied to two 4"vents. Although, almost all the heat this lamp generates is from radiation, not thermal loss of the LEDs, so the heat sink is barely warm. Lights up to 16" over canopy to allow growth while on vacation. Ppfd at canopy 800. Room temp 81, humidity 73. Auto water time is 30 sec per pot.

Well, this week brought some new challenges. Never repeatedly switch an inductive load with a relay without a snubber. Killed exhaust fan control relay and was up to 91% for a day or so. Swapped in a SSR, and it's much better. Nute mix: N:P:K:Ca:Mg:S is now 1.25:3:2:1:0.5:0.6 Took the advice and defoliated most of the major fan leaves around the inside and center of plant to get more circulation and expose more bud sites. Left most major fans on perimeter to keep sucking up light.

Ok, back from vacation! Reservoir worked out perfectly, both plants are throwing out pistels, no stretch to speak of, and leaves are huge and green! 4/25 - chopped back a bunch of fan leaves to open it up and expose some more bud sites. I should probably chop back some of those to avoid a bunch of larf, but I'll get around to that soon.dee 4/28 - digging into optimal NPK ratios for flower, and came across this study: https://www.frontiersin.org/articles/10.3389/fpls.2021.764103/full Some very, very good info. I tried to re-create the 10:3:10 ratio using the Fish Fertilizer for a bulk of the N component - an absolute fucking mistake. After 2 days, it smelled like I was keeping a corpse in the basement. So, I just deep cleaned the reservoir and got all that nasty stuff flushed out. Working up a new mix now. Stay tuned (just kidding, nobody has even looked at this grow, so far as I can tell. Whatevs.) OK, New mix for 10:3:6.5 is: 250g MC Part A, 170g Calcium Nitrate, 20g Epsom, 130g Urea in 10 gallons yields ratio that pretty matches the optimum from the above study - 200mg/l N : 60mg/l P : 130mg/l K : 65mg/l Ca : 35mg/l Mg : 42mg/l S Gonna let it fly and see how it turns out. Might need to tweak the weights a bit to hit my target EC, but keeping the ratios the same.

4/30 - everything is going great. No bugs. No burnt or turned up leaves. Just pure green and happy buds. PPFD 760 across canopy, still no CO2 and I won't attempt it this grow, humidity still in check and rock solid using the vent fan to control RH. Probably harvesting before summer humidity, so I can probably avoid any dehumidifier use. Might dial it back depending on bud density, but I'll cross that bridge when I come to it. For now, trying a new, non-fishy, nutrient mix that goes against most of the accepted science for flower phase. N:P:K:Ca:Mg:S is 200:60:130:65:33:41 that I'm slowly ramping up to 1.9EC. Here's the study I'm working from: https://www.frontiersin.org/articles/10.3389/fpls.2021.764103/full Time will tell. This study mentions that the inflorescence dry weight was directly proportional to the size of the plant, so bigger plant = more trichomes. Nice, BUT, it also mentions that the high N, high growth plants had 20-30% lower THC concentration. So instead of a 25% THC killer, you might get 19% THC bud, but a lot more of them. Theory is that the lower N fertilizer rate (like most 1:3:2 or 0:3:3 regimes) cause nutrient deficiency stress, and plant stress = greater cannabinoid production. OK, so what if we take the best of both worlds - max growth with the 10:3:5 ratio, combined with a different source of plant stress. In this study on plant stress vs. cannabinoid production (https://journals.ashs.org/hortsci/view/journals/hortsci/54/5/article-p964.xml) they use drought to stress the plant, without affecting growth or inflorescence dry weight, increasing THCA and other cannabinoid production 43-50%. The timing of the drought cycle relative to induction of flowering is crucial, and they started their drought cycle at week 7 of flower. So, should I try drought-stressing these bitches in a few weeks? Stay tuned, oh, and maybe I could get one freakin' like from all y'all? I'm pretty chuffed with this newby grow :) 5/2 - EC to 1.82, pH 5.5, PPFD to 950

I really can't believe how well this is going. Absolutely perfect leaves from the bottom to the top. Buds are forming out nicely. Leaves are frosting up. Wish I had a screen or a frame so I could open up the center of the plants a bit more, but maybe I'll set up a ring or two this weekend. PPFD is maxed out at about 1200 in center and 950 at edges. Nute concentration is the same as last week. Bumped up the pH from 5.3 to 5.7 to mix it up a bit. Nute ratio is 1.25 MegaCrop Part A, 0.85 Calcium Nitrate, 0.1 Epsom, and .65 Urea. Made a concentrated mix on the stir plates, then added to reservoir until total EC was 1.9. 5/11 - very slight burnt tips. Dialed it back to 1.80EC and 5.6pH. Same nutes. Lollypopped both plants today, but left a couple of the lower buds that were monsters and had good access to light. Supercropped the two mains on Zoey. Left Twiggy alone (for now.) Note to self: 11.6oz wet trim and larf this AM

5/13 Another week starts, full of growing bliss! Twiggy and Zoey are doing great, and the recent lollypopping should start pushing the main buds to really bulk up. One more week of growth, then I plan a week of drought stress to see if I can crank the cannabinoids up higher. Why not? Wish I was working with clones so I could do a proper A/B test of cannabinoids with a Cannalytics TLC test. Added 2nd feed cycle at mid-day. Same fert mix, EC1.8 5/16 - cut out 2nd feed cycle and just upped the time on main feed to get 10% runoff. EC 1.78, pH5.6, PPFD 1400-980 on edges. CO2 mostly in 600-700 range because wife's office is in basement too, and she's putting in a lot of hours 😋 5/17 - Yes, the plants look great. Yes, there is no sign of stress at all. But, for fucks sake, I let the EC of the Leachate get away from me. Measured what was going in just fine, but only checked leachate in first few weeks. Checked today and it was about 3.8EC 😮 SO, cleaned out fert tank and pumps, filled with tap water, pH to 5.4 and added the rest of my Silica Boost. Flushed both pots with about 5 gal of nice, clean water, and got leachate EC down to 1.6. Yay! Now we're almost ready to drought stress these gals! Going let these drain down a bit and dry out, then give one more feed by hand at 1.5EC before inducing some stress. 5/19 - Reservoir is empty of the flushing solution, so starting drought stress as of this morning. We'll see! 5/20 - speaking of stress, exhaust fan SSR failed and didn't vent at all today. Temperature up to 92 for a few hours 🙄😬😡

Twiggy and Zoey will be hurting this week. Trying a bit of drought stress to see how it will affect the terps. They look great going into it, so we'll see how it goes. Pots have dried out and are super light as of 5/21AM

Well, this week was a learning experience. Tried drought stress, went wayyyyy to far. Zoey is pretty toasted, Twiggy bounced back, but some leaf damage. 3 days dry was too much in coco. 2 days should've worked, but I got tied up at work and thought it could handle one more night. I was wrong. Zoey's leaves are all pretty crispy. Buds still seem moist, and there is some nice dark green growth poking out from under the dead stuff. Who knows, give 'em both a couple of weeks. Trichs are still mostly clear.

Well, well, well! After my colossal fuck-up with the drought stressing, Twiggy seems to have bounced back. But let's talk about Zoey. Zoey was pretty much dead. After 10 days of regular feeding, I didn't see any new growth on about 60% of the buds, so I harvested 60% of Zoey. The other 40% of buds showed some new growth popping out of the top and bottom of the buds, so I'm going to let her go for a while. Twiggy fared much better, and is still putting on new growth on all bud sites. You can actually see a band of dead sugar leaves around the buds where it was fried, but even the dead leaves are still loaded with trichs. So, we keep going. Checked trichs from Twiggy and Zoey with microscope and, even though there are a fair number of brown and tan heads, most of them are still clear. So, we keep going. Of the toasted buds I harvested from Zoey, I got 2.83oz dry. Still at 1.8EC, 5.6pH, Nitrogen heavy feed, 1400PPFD. N:P:K:Ca:Mg:S is 200:60:130:65:33:41 Before i drought stressed them , they were f'n perfect. See week 10 for reference. Here's the nute study I'm working from: https://www.frontiersin.org/articles/10.3389/fpls.2021.764103/full 6/8-starting flush. Tap water with a smidge of PK, 0.5EC, 5.5pH.

Well, the drought stress in week 11 really fucked my plants up, but Twiggy recovered, while Zoey was hurt pretty bad. If I did nothing, I'm betting harvest would've been 25% more, and Zoey's buds wouldn't look so crappy, but overall, I was so happy with this grow! I was under a time crunch, so only did minimal veg for 4 weeks, topping once. Daily watering with 1.8EC mix that was pretty consistent. Kept pH between 5.5 and 5.8. Kept tight control on humidity and temperature up to mid flower, then kept air circulation on to keep room humidity around 55% Things I'd do differently: 1. Veg longer - I'd love to try a mainline 2. Canopy control - wish I had spent the time on a SCROG screen, or at least a couple of rings. 3. More light sooner into flower. Waited about 4 weeks into flower before maxing out the light. Probably could've bulked them up significantly if I started earlier 4. Drought stressing - For Fucks Sake, keep a close eye on your plants, and the minute they start to wilt, get the water back on 'em!!! 5. Measure your run-off more frequently for salt build-up. Didn't have any problems, but it's a good best practice. 6. Set up proper closed-loop environment to allow for CO2 enrichment. 7. Set up a clone environment before you get to flower. Oops. Things I was happy with: 1. VPD control system (heat, humidity) during veg and early flower worked flawlessly. Never any nute burn, and super healthy plants. 2. Sterilized soil and grow-room before starting - never had a single bug or any mold/mildew issues. Used a MERV 13 filter on the air intake, exhaust through carbon to crawlspace. 3. Coco/perlite mix - super drainage, low build-up, very healthy roots. 4. Power meter - neat way to measure what's really going into the grow, so when your wife complains about power usage, you can show her the real numbers. 5. Photone app on Android S20 - Knew where my PPFD was for optimal growth control. 6. REX-C100 PID controller for toaster oven - super tight temperature control comes in handy for decarbing as well as toasting oak for moonshine.