leafs tips burn (nutrient burn / light stress / .. ?)

in addition to the rest, that's too much dli in center. even if a plant adapts to it, it's not using the excess energy and just wasting electricity and adding extra heat. CO2 is the limiting factor for photosynthesis. There's no circumventing that. Unless you are boosting co2, it's not making use of that excess light. could be contributing to chlorosis and thin leaves at top, but so could an over-abundance of P and/or K, which also sounds plausible given description.

Be thorough with leeching if you do decide to flush and reset ec, No3- nitrogen is highly mobile in soil. Nh4+ is immobile in soil and will not readily leech. both nitrogen deficiency and excess can delay flowering development in plants. A moderate amount of nitrogen is crucial for vegetative growth and early flowering, but excessive or deficient nitrogen levels can negatively impact the flowering timing. In future I would stick to mineral fertilizer that is readily available for uptake. For a easier time controlling what's going on inside the medium.

Everything your feeding is organic. What does that mean? It's not readily available for uptake until microorganisms break it down into more palatable size. Why does that matter? Nitrification is process by which plants converts organic nitrogen firstly into nh4+ then processes that into no3- At ph of 6.2 nitroficTion is about 20% as efficent as it would be at 7.0. Your ec if full, but all your nitrogen is locked up organically not broken down yet and as nh4+ But is not being converted to no3- fast enough this will turn your medium acidic. When ammoniacal nitrogen exceeds 20% if the total nitrogeb it can lead to various detrimental effects, including inhibited growth, reduced photosynthesis, and potential tissue damage. Excessive ammonium can disrupt nutrient uptake, particularly calcium, and lead to an imbalance in carbon and nitrogen metabolism. Best of luck with recovery.

Hey 👋 Yep, looks like slightly overdosed. But nothing crazy so far. Just give them plain water next 1-2 times and everything should be fine. Do you use the fertilizer with each watering ? BioBizz recommends to feed max. 2-3 times a week acc. To schedule.

Yo bro, that’s early nute burn nothing crazy yet, but it’s def showing on those tips. Probably just from the sudden jump in strength. If you tripled the feed compared to last time, especially in Light-Mix, it makes sense. That soil already holds some stuff, and organics can build up slowly. Dial it back a bit today. You don’t need to flush unless you went really overboard, but I’d drop things like: Root Juice, roots are done, save the bottle. TopMax can stay, just keep it low. Bio-Grow only if they look hungry, otherwise focus on Bio-Bloom. Try sticking around 5–6 ml/L total for now and see how they react. Your girls still look healthy and happy overall — this is just a heads-up from the plant, not a full problem yet. You caught it on time. 🔍💪 Let us know how they look after the next watering 👌

Yeah. 150% would have been completely sufficient, so I would now "only" water with 100% and when she has recovered, increase to 150-200% of the BioBizz schedule. 200% is meant for strains like the Critical, you can almost never give them too much. 300% is really a lot…