Nutrient shock?

I can't see any issues here. Just give the lady some time and be patient. You will get the reward :) Just go easy on bloom nute at the first couple weeks of flowering. Side lighting helps with the yield a little bit, but please keep the distance and also keep an eye on the temperature. Cheers

don't see any problem, u gave P that's bs u see change in coloration, doing so u fixed p def

Too early for bloom.............your plant still needs the extra nitrogen in the grow formula to elp withe the "stretch". Pre-fkowers is not actual flowering, only an indication that flowering is about to commence. Continue with grow for another 10-14 days before changing to half grow and half bloom for 7-10 days and only then switch to straight bloom nutrients. Honestly can not see anything in the leaves that would worry me too much, a bit over fed maybe, but overall ok. Flushing is a last resort measure when things have gone horribly wrong and should not be used as a reaction to minor issues. However, I am sure John will debunk everything we have all suggested, throw in some abuse, then tell you exactly what to do, he is God after all!

hi Luca.... Ich denke es ist eine Stressreaktion der Pflanze...... Die Düngerumstellung und der Lichtstress mit dem zusätzlichem Licht, waren wohl etwas zu viel für die Lady....... Gönne ihr mal ein paar Tage ohne Stress und sie wird sich wieder erholen .....😉 Viel Glück

This is bauen/light stress from the side light + intensity swing, not a nutrient problem. The pale, washed-out look on your leaves is classic photoinhibition the plants got blasted with that side light after being adapted to 600 ppfd, and now they’re struggling.What happened: You added side light (probably too close or too intense), the plant panicked, then you cut your main light to 400 ppfd. The problem is the combination and the sudden change not the nutrients. Flushing won’t fix this. Your nutrients are fine. What you need is stability and time for the plants to recover. leave the side light OFF for 3–5 days. Keep your main light at 400 ppfd and let the plants acclimate. Once they stop showing stress (leaves should start darkening back up), then you can gradually introduce the side light at a very low intensity, far away (18”+ distance). Ramp it in slowly over a week. Your Biobizz Bloom is working fine the issue is environmental shock. Stop adjusting and let them settle. The pale color will fade as they recover. Flushing just adds more stress when they need stability.

18h and ~600ppfd should be fine.. but if it needs 5-15% less, that's possible, too.. it's a good spot to start. 400ppfd (if accurately measured) is probably lower than necessary. 12h you want 800-900ppfd. You need to reference DLI. DLI is what matters. PPFD without hours of operation is half useless. PPFD is not a single point measurement. So if you or an app is calculating it from a single measurement, it's not likely an accurate value. Also, phones merely convert lux using a conversion factor that may or may not be entirely accurate. It'll depend on the spectrum flux and how it varies from whatever they decided was an average grow light spectrum. Flushing is pretty stressful and should be avoided as best you can, not turned to as a fix-all for minor issues. based on any leaf chart, yellwing inside-out on top leaves could be S-deficiency. Looks minor. If it fills in quickly, may not even be a problem. Other things can also cause chlorosis and skinny leaves in new growth -- too much p or k, if you boosted it recently is a potential cause, too. leaf symptoms are not discrete. you will have to use more information to eliminate possibiities and make a common sense decision on what to try first. I also see it on the 2nd level of leaves under the top, so i doubt it's light-related. I'd wager a slight boost to S concentration while maintaining other levels of nutrients would solve this problem. Since it's a small issue, i would not make a drastic change to S, though. Start small... can incrementally increase it. This stuff takes time. don't expect immediate results overnight. The rate at which it is progressing is the key.. if it regresses, you know you've course corrected, but then keep an eye out for going too far the other way... rates of change over time and trying to find that equilibrium with environment is a matter of trial and error.

Hey Luca, honestly it looks more like your ladies are just reacting to the transition into the flowering phase rather than a full-on nutrient shock. When you switch to Biobizz Bloom and adjust your lights, the plant naturally shifts its energy, and that bright lime green growth in the center is usually just fast-growing new tissue that hasn't filled with chlorophyll yet. Since you've already flushed them and dialed back the PPFD to 400, I’d suggest just giving them a bit of time to stabilize without changing anything else. Over-correcting can sometimes stress them more than the initial change did, so keep an eye on the new growth and if it darkens up in a few days, you're all good. Happy Growing Growmie🌱