Autoflower Seedling Stage Problem?

Phosphorus (P) deficiency can cause disfigured leaves, while often described as "stunted" or "spindly," the overall lack of energy (ATP) causes leaves to lose vigor, appearing weak, thin, and drooping downward. Phosphorus (P) deficiency in plants can be directly caused or exacerbated by hypoxia (low oxygen availability in the soil), typically resulting from waterlogging, flooding, or poor soil aeration. 16-24°C converts to 60.8-75.2°F, that's a metabolic slog at 75F, Oxygen can easily be locked out in a sense if the medium is oversaturated, even if oxygen is present. Optimal temp for photosynthesis is a internal leaf surface temp of 86F, The enzyme Phosphofructokinase-1 (PFK1), which acts as a key rate-limiting step (pacemaker) in glycolysis during cellular respiration, generally functions optimally at warm temperatures, typically in the range of 86°F Evaporation is a key, energy-dependent (endothermic) way water moves into the atmosphere, but gravity and biological processes (like transpiration) are equally essential for moving water through and across the surface of the earth. Transpiration can only pull where roots can penetrate, transpiration is the primary process that maintains the water balance (and thus the turgor pressure) necessary for structural support, Turgor is created when water enters cells via osmosis, creating a positive pressure (turgidity) that keeps the plant firm and upright. Transpiration (water loss through stomata) creates a negative pressure (tension) in the xylem that pulls water up from the roots. While this transpiration stream brings water to the leaves, excessive transpiration leads to water loss, which reduces the turgidity in cells, causing them to wilt. transpiration keeps the plant hydrated by pulling water upward, but it is the osmotic movement of water into the cells that generates the actual turgor pressure. Root penetration is a fundamental biological process driven primarily by turgor pressure. Soggy wet low energy cold metabolic conditions, potential hypoxic conditions, locking P. Phosphorus (P) is widely considered one of the most, if not the most, critical nutrients for early seedling development and establishment. It is essential during the first 2–6 weeks of growth to support energy transfer, cell division, and root development.

Hey Growmie 💚 At week 3, those symptoms together usually point to root-zone stress, not a single deficiency. A few things stand out to me: Temps: 16°C on the low end is quite cold for an auto, especially for the roots. Cold roots slow growth and can cause twisted, droopy leaves and discoloration. Humidity swings: 40–75% is a big range. Rapid changes can stress young plants and mess with transpiration. Very airy mix: 40% perlite + vermiculite drains fast, which is good, but it can also dry unevenly and stress roots if watering isn’t dialed in. What I’d do: Try to keep temps more stable, ideally 20–24°C, especially at the root zone. Aim for more consistent RH (around 60–65% at this stage). Check watering — avoid frequent small waterings. Let the medium dry slightly, then water thoroughly. Don’t push nutrients yet; Lightmix + an auto at day 22 doesn’t need much. If the new growth starts coming in healthier, you’re back on track. Autos are sensitive early on, but they can recover quickly once conditions stabilize 🌱