Welchen Mangel hat Sie?

Typically when I see that burning in the veins of the leaves its a PH issue. Biobuzz has literature on the PH range for their products and they advice against anything below 6.2. your grow is at 6.0 on the diary. I would raise your ph to 6.2-6.5 even 6.8. and see how it does. The nutrients are all available and don't need to be broken down, I have a feeling they drift a bit in the medium and make it more acidic so higher starting ph is likely better. here is a leaf chart, can help diagose some of the leaf sysptoms but when its more then one, can get confuseing. https://420life.com/wp-content/uploads/2021/10/Marijuana-Leaf-Deficiency-Chart-scaled.jpg

A mobile nutrient that causes interveinal chlorosis that remains darker on the midribs working out to lime green is magnesium. Calcium Ca and magnesium Mg are both cations, meaning they are positively charged. While nitrogen typically forms covalent bonds in nitrates NO₃⁻ or ammonium NH₄⁺ depending whether it's synthetic or organic. Ph is all about balance. If you add 95% Cations to your medium which was alrdy at ph of 7 you are skewing the balance 7+. Closer you are to a ph of 7 the higher % of cations are in your medium. If you are at a ph of 6.2 and you added 95% cations to your soil ph would rebalance somewhere 6.8 and at 7.0 the cec would be 100%. Only mobile nutrient that fits is magnesium being on older growth. But I'd be checking my ph make sure she is in range.

What if ? All ur problems due to CalMag? CalMag excess leads to K lockout At week 1-2 all was fine, then constant feedings with this shit made a buildup and now it looks like Mg deficiency, BUT it just can,t be! There is actually 2 options: -Ca buildup that leads to Mg,K lock -Mg buildup that leads to Ca,K,P lock I,d say its 2nd SO... Please THINK a little for yourself or u can use more CalMag shit or even epsom salt and we'll see u soon... Yeah...

Hey! It looks like your plant is showing signs of a magnesium deficiency, with possible early potassium issues as well. The interveinal yellowing (green veins, yellow between) is classic Mg deficiency, while the brown necrotic spots can appear later with Mg problems or also indicate low K. Since it’s happening on the lower/older leaves first, it’s definitely a mobile nutrient issue. What to do: Check pH – In soil aim for 6.2–6.5, in coco/hydro 5.8–6.2. If pH is off, nutrients like Mg/K can’t be absorbed even if they’re present. Add magnesium – Use Epsom salt (magnesium sulfate) at ~0.5–1 g/L in your feed, or a Cal-Mag supplement. Watch potassium – Especially important in early flower. Make sure your base nutrients provide enough. Monitor new growth – Damaged leaves won’t recover, but new leaves should come in healthy once the issue is fixed. I always recommend a foliar spray with Epsom salt or a solution like BioTabs Boom Boom Spray for these kinds of deficiencies. Have Fun and enjoy the ride! 😊