#4 - AutoPots und Sonnenerde

Metterling 18.03.(V1) – Repotting into small pots The seeds were planted in small pots with moist seedling soil, mycorrhiza, and nematodes. The plants are already showing strong stretching; I planted them a bit deeper this time to create more space for the soil. Watering probably won't be necessary this week.

Metterling 25.03. (V8) – Preparing the AutoPots with Living Soil and starting substrate management To avoid watering mistakes and high maintenance effort like in the last round, I'm going with AutoPots this time with 25 L volume and Living Soil (sun soil with 20% perlite). The goal is to achieve as autonomous a supply as possible without additional fertilization. The perlite should provide better aeration but could also reduce nutrient availability – that's why I'm additionally using AirDomes + AirBase (still deactivated). Preparation involves intensive soaking in the bathtub, target weight per pot ~16.8 kg. 29.03. (V12): Watered each with 2 L of nematodes 30.03. (V13): About 0.8 L of drain per pot Humidity is passively increased using a wet towel in the tent. Air circulation through a PC fan array. Lighting currently set to level 3 (~DLI 23).

Metterling 01.04. (V15): So far, they're developing quite well. The soil moisture seems to be back in order. The left plant is shooting up the most (it does have XL in its name), the middle one is the bushiest, and the right one is taking it easy. On the right, I've also measured a noticeably lower light intensity due to the towel, so I should probably swap it for a white one. The lighting has now been increased to level 4 (about DLI 28). However, I'm starting to see some unsightly leaves in the lower levels. Not all of them, but apparently a first sign of a deficiency. With the Living Soil, pH and Cal/Mag shouldn't be a factor, at least not this early. I suspect the soil hasn't generated enough nitrogen yet, or I washed out what was there with the heavy watering three days ago. I'll keep an eye on it for now. I should probably start thinking about training soon. I'll keep an eye on Cal/Mag and pH in the water reservoir; it can't hurt. 03.04. (V17): The existing damage is getting worse, but the intact leaves still look good. The soil can take water again, but I want to water from the top first. So today, I watered 0.5L per plant with corrected pH and Cal/Mag. 04.04. (V18): Today, I started the AutoPot system with AirDomes. The tank has 45L of corrected pH and Cal/Mag water. 06.04. (V20): Some leaves are affected by damage, but I feel like the plants are growing very healthily. The top layer of soil is quite dry (which the Living Soil probably won't like - I need to think of something), but according to the soil moisture meter, the soil moisture has increased a bit and is right in the ideal range. 07.04. (V21): Today, it was time for my lovely bushes to get pruned. I decided on the adjusted main-lining technique from Hyperactive Highs and plan for 16 tops per plant. It turns out that the Painkiller XL has a very asymmetrical node distribution, which I didn't expect (photo). Therefore, I will start two mains with it. I think if I position it as a middle plant, I might even achieve a less compact distribution of the tops. We'll see. Maybe I'll end up working with 8 tops per plant after all.

Metterling From now on, training will be done diligently and I’ll be adding more every 2 days. I try to remove any unwanted nodes as early as possible and I remove leaves as soon as they develop too much, so that less light hits the bud tips.

Metterling 15.04. (V29)

Metterling 04/22. (V36) To combat the fungus gnats, I applied about 2cm of perlite, watered with nematodes again, and distributed fresh yellow sticky traps.

Metterling 29.04. (V43) From April 30th to May 4th, the plants had free rein and I was away. However, they handled the circumstances pretty well, I'm thrilled with the watering system over the reservoir! The clover is already peeking through the perlite. Of course, I'm not sure if the soil is still too wet. But Living Soil shouldn't get too dry, so what good is the soil life if I always keep the top centimeters dry and only below does the moist soil start? The fungus gnats are just impossible to control. They did decrease significantly when the perlite + nematodes were introduced, but now that more foliage is coming in, it's getting worse again. They also don't seem to be getting caught well on the yellow sticky traps anymore. Have I created a new, smarter evolutionary stage of fungus gnat?

Metterling 06.05. (V50): It's pretty crazy how much growth is hindered by pruning. Still, I'm trying for a long veg so the roots can develop as well as possible. I'm hoping for a better-fed bloom. 09.05. (V53): Light increased to level 5. 12.05. (V56): Starting today, the T3 humidifier from AC Infinity has moved in, I'm hoping for an even more stable regulation: VPD: Day 1.1kPa, Night 0.9kPa (extraction fan minimum level 1), I think I should slowly switch to flowering, otherwise it might get too warm in the attic during bloom. It's also getting difficult to train them further out. So today, I tied everything up nicely, and starting tomorrow, it's into flowering.

Metterling 13.05. (V57): Today I switched to 12/12, from 7 AM to 7 PM, so that the BKW can take care of the supply as much as possible. The lights are now set to level 6. 14.05. (V58): The fungus gnats seem to be getting worse again. I assume they're somehow stuck down in the AutoPots in the reservoir. I've stocked up on yellow sticky traps. I believe the plants are enjoying the conditions right now; the leaves look good, and I don't see any new damage. 15.05. (V59): The lights have been hung a bit higher now because they look a bit stressed in the middle, where the light is stronger than at the edges. The light intensity has been increased to level 7 (PPFD: 700, DLI: 30). 17.05. (V61): The water reservoir has been refilled. 40L of tap water, 10g of PH-, 2.8g of Epsom salt (16%), 65g of CalMag - PH 6.5, Cal/Mag: 3.5/1, Calcium 100mg/l. 18.05. (V62): I found a mistake. I measured my leaf temperature and found that at an air temperature of 24 degrees, the tops in the middle averaged 19.5 degrees, the outer ones 17.5 degrees, and the fan leaves below were always about a degree cooler than their tops. I had only set a 2-degree offset in the controller, and this difference is, of course, very high and leads to a much higher VPD than expected! The sensor was hanging about two fingers above the tops; now I've brought it as close as possible to the height of the tops, let it calibrate a bit, and at a (now correctly measured) air temperature of 24.5 degrees, I now have about 22.5 degrees at the tops in the middle and 20.5 degrees at the outer ones. So I'm almost on target in the middle and will adjust the offset to -3 degrees. BUT: I need to ensure that the temperature and PPFD values in the canopy become more homogeneous! In the middle, I have about 750, outside 650 PPFD. 19.05. (V63): In the morning, before the light phase, I measured: air temperature 20 degrees, leaf temperature in the middle AND LEFT 19.5 degrees, right (where the air inlet is) 18.5 degrees. So I obviously have an airflow that cools the leaves on the right more. I need to make sure that the intake air comes from both sides and is best distributed evenly under the plants.

Metterling 20.05. (F1): Increased light intensity to level 8, lamp distance set back to 30 cm. The goal was a more homogeneous lighting (~750 PPFD). I feel like the fungus gnats are slowly running out of air! Especially the lower yellow traps, which are just above the perlite, are well filled and not many are flying around anymore! I might wait a bit longer before adding more nematodes. 21.05. (F2): Compared to 17.05., stress indicators are increasingly showing: Leaf tips are curling slightly upwards: indication of transpiration stress Brighter new growth in the upper area: possible sign of nitrogen deficiency or temporary under-supply from the soil, maybe due to increased demand from stretching? Measures for relief: - Closed AutoPot valves: substrate should dry out slightly for 1–2 days to promote aerobic activity and nutrient mobilization - Reduced light output to level 7 (~650 PPFD) - VPD target (day/night): 1.0 kPa - Temperature reduction: day 25°C, night 22°C - Optimizing humidity distribution: humidifier hose now positioned below plant height at the intake channel to bring mist into the canopy zone faster and avoid inefficient triggering of the exhaust fan The focus for the next few days is on stabilizing environmental conditions and promoting soil life. 23.05. (F4): The AutoPots were activated again today, the stretch is progressing quickly – the sensors are now regularly disappearing under the leaf canopy. The brighter leaf colors in the new growth area continue. However, since the plants are showing stability and no new symptoms are appearing, the light (level 7 / ~650 PPFD) and VPD (1.0 kPa) remain unchanged for now. Observation: Some of the tops are lagging significantly in development. To optimize light distribution and possibly give the weaker shoots a chance to grow, I’m starting to SCROG now. If it turns out that some shoots are falling behind significantly and not catching up, I’m considering cutting them off and focusing on the dominant bud sites. Additionally, I discovered an extra node level per shoot in the upper tiers that was not originally planned (goal: 1 bud site/shoot after main-lining). The decision is still pending on whether to remove these shoots as well – tendency: yes, as long as they don’t have a real chance for even development. 24.05. (F5): Today I removed the new shoots (about at the height shown in the photo). I also installed a SCROG net, tried to distribute the tops as evenly as possible, and defoliated a bit at the bottom while I still could. I completely cut off two or three very small main shoots. It’s only day 11 of flowering, one should probably defoliate later, but I wanted to work on it a bit more before the stretch is over. 25.05. (F6): The tops that were lying flat under the net yesterday have stood up quite nicely. So today I tucked them a bit more evenly and will definitely continue to do so in the coming days. 26.05 (F7): The stretch continues, the leaf color has neither improved nor worsened. I actually wanted to increase the light and VPD tomorrow :-/

Metterling 27.05. (F8): I'm not happy with the state of the plant. The leaf color is still too light, which indicates problems with nutrient uptake. Since PPFD (~650) and VPD (1.0 kPa) are in the optimal range, I rule out transpiration stress as the cause. A possible cause is too high humidity in the substrate of the AutoPots. This can lead to oxygen deficiency in the root area. It affects both the roots and the microbial soil life. As a result, nutrients are not made sufficiently available. Measures: - Turned off AutoPots today (planned until F9/F10) - Light and climate parameters remain unchanged - The plan is to repeat the shutdown once a week in the future to regularly aerate the substrate While shutting off the AutoPots today, I remembered that there is still quite a bit of water in the reservoir, which also needs to be processed by the plants first. This means that the drying phase for the plant will naturally start much later. I didn't consider that last time! Today I emptied the reservoir when shutting it off (about 400ml per pot). 28.05. (F9): I think the leaves are looking pretty good again now. However, the difference in the photos is not so easy to see due to the strong lighting. I've set the target VPD back to 1.1 kPa. 29.05. (F10): To continue dealing with the fungus gnats, I watered 0.5l with nematodes from above. 30.05. (F11): The next few days are going to be quite warm and humid, so I'm trying to keep the temperature below 27 degrees, and the VPD won't be able to rise much above 1.0 kPa for the rest of the week. 31.05. (F12): Today I increased the light to level 7 (about 750 PPFD), reactivated the AutoPots, and refilled the water reservoir.

Metterling 04.06. (F16) – Lush growth, differentiation of light distances, and outlook on further shoot management The upper leaves now have a noticeably richer green than some time ago. They look healthy, show no signs of burns or light stress, and the buds are visibly developing further – they are thickening and starting to connect. The Painkiller XL continues to stretch strongly and reaches about 20 cm from the lamp at its highest point, showing no signs of stress reactions. To ensure even light distribution, I have now mounted the lamps on the right and left at slightly different heights, resulting in an average distance of about 28 cm. 06.06. (F18) Today, I heavily defoliated. I know I'm a bit late, but I wanted to make sure the plants are as stable as possible. I removed almost everything under the scrog net; it might have been a bit too much, time will tell. 09.06. (F21) The water tank was empty, so I refilled it today. pH at 6.2, adjusted with Epsom salt and CalMag. Probably unnecessary.

Metterling 11.06. (F23) - Start of the main flowering and adjustment of climate parameters The plants are now clearly in the main flowering stage. The lighting has been increased to level 8, which corresponds to a PPFD of about 800–850. The target values for the climate have been adjusted to 23 °C and 45 % RH (about 1.22 kPa VPD). Considering the upcoming heatwave with temperatures over 30 °C, it remains to be seen how well the mobile air conditioner can keep conditions stable in the attic. The outer plants at the top continue to show bright leaves, and the Painkiller XL is still losing lower leaves. I've now topped the clover; I probably should have done it earlier, but it didn't make much difference due to the perlite. 13.06. (F25): I drained the AutoPots today and deactivated them for two days, hoping to improve nutrient uptake. Positive note: The fungus gnat infestation seems to finally be overcome thanks to the nematodes. 15.06. (F27): Turned the AutoPots back on.

Metterling 22.06. (F34): It's still too warm, sometimes up to 28°C in the tent. At these peaks, I adjust the lighting down a notch or two to avoid worse issues. Unfortunately, the lower level is still suffering. I've turned off the AutoPots again.

Metterling 24.06. (F36): AutoPots turned back on, but it's not getting any better. Apparently, the Living Soil just doesn't have enough power anymore. The leaves in the upper area also don't look ideal anymore.