Whats the problem, is it Windburn?

Doesn't look too bad, just a little twisting and new growth looks fine, not the end of the world :) 5 ml/L Bio-Grow is way too much, and only once is not how BioBizz is meant to be used. You should perhaps try reconsidering your watering and feeding method to better fit your chosen pot type and fertilizer brand: Watering fabric pots with soil/peat based medium: 1. Get saucers or a solid 60x60cm bottom tray, you need to let the fabric pot fully saturate with water to get the most out of them 2. Water with 25-33% of pot size (/in your case 2,5L to 3,3L per plant) at this point it means watering about once per week, later it'll be 2-3 times per week 3. Never let the pots fully dry out then the medium get hydrophobic and the plants don't get the water they need, practice lifting the pots to feel if they're light and water when you no longer feel the weight of the water but the medium is still slightly moist Using BioBizz: 1. Use Bio-Grow with every watering, at this point 2-3 ml/L and gradually increase up to 6 ml/L ish if you veg for long - BUT if your soil mix is pre-fertilized it should be less, like half 2. Use Alc-a-Mic, it's the one of two BioBizz add-ons worth buying (the other is Top-Max for mid/late flowering) 3. I don't know if it's the advice you want, but having used BioBizz for 8 years, I recommend not using it... :) At least not indoors - It's way too difficult to use correctly and super slow-reacting and it's not proper organic anyways, and it's just so much easier (and less gross and stinky) to get way better end results with simple mineral nutes where you use one bottle in veg and one bottle in flower.

To me, it looks like toxicity from feeding too much or too often..............or both. It does not look like a watering issue to me.

Yeah I'm also thinking from how heavy the leaves look it could be a watering issue. I like to saturate the grow medium then wait until its quite dry, can be 3 to 5 days inbetween waterings.

By leaf position, would say root zone and oxygen lack related. Overwatering or wrong watering pattern. Could be low temps too, if your nights colder than 17-18 Celsius - you can get such state too. If its soil - its mostly overwatering aka you water pot , while he was still wet. Lift pots to understand when girls need refreshments.

I couldn't find any information about your water ph, growmie. Also your diary states that you are feeding her 5ml/L bioBLOOM? she's not even in flower yet and might only take grow at this stage and probably can even go without it because it's only 4 weeks old... I suggest you water her next time she dries with just ph'd 6.3 water until 20% of what you pour comes out as runoff. Measure its ph and ppm as well. And try weighting in your pots with hands before and after you water it could help understand easier when your plants need watering as well as finger poking method :) Good luck, buddy!