Ah thats common. You See, those things you hold in your fingers are normally found on your plant - to find them in your fingers means you stressed the plant by ripping leaves off of it. No but in all seriousness :

There multiple deficiencies that i personally See in those leaves, Magnesium being one of them. Instead of going out and buying a whole lot of shit youll prolly Never need - try adjusting the ph of your water to around 6. the adjustment is to See if maybe your plant is locked out of nutrients.

[–] Gingerino@lemmy.zip 1 points 1 month ago

thank you for your availability. I'll tell you right away that I don't buy random things. I fertilize my plants with the complete PLAGRON organic line: Grow/bloom algae etc... I always check the pH of my water at every irrigation, furthermore the soil I put is rich in earthworm humus, guano, perlite and a good dose of Mycorrhizal fungi right from germination. I detached that leaf immediately after both water and heat stress (the cooling system turned off while I was away, reaching 37/38 C° with 20% humidity for almost 36 hours! It's a miracle that they didn't die, you can see that they are F1 genetics. ☺️. in my opinion that is a light/heat damage in a dry environment. as you can see now they're back to being nice and green. don't you think?