the plant is suffering from a nitrogen deficiency due to a major calcium and magnesium issue, the black spots on the leaves are necrosis caused by the lack of calcium and magnesium, try adding calcium and magnesium to the nutrient solution and then in the same solution add what you normally use until you reach an appropriate EC, I understand that when trying to address a deficiency of calcium, magnesium, and nitrogen you have to be careful that the pH isn’t too high and that it doesn’t hinder nitrogen absorption

That doesn’t look like classic nutrient burn — I’m not seeing crispy tips or dark, clawed leaves. It looks more like a deficiency, most likely nitrogen or possibly magnesium, especially with the overall paling and lighter inner areas. Since you’re in flower, some fade is normal, but this seems a bit early and more pronounced than a natural fade. I’d check your pH first to rule out lockout, then slightly increase base nutrients (not aggressively) and make sure there’s enough Mg available.

Salam Habibi! 👋 Welcome to the flowering stage, where the line between a hungry plant and a burnt plant gets very blurry! 🌸 Since I cannot see the photos of your specific plant right now, let's look at this through the lens of Modern Engineering so you can instantly diagnose whether your plant is suffering from Nutrient Burn or a Deficiency! 🛠️ Here is the mechanical breakdown of how your plant shows symptoms: 1. The Mechanics of Nutrient Burn (Toxicity): 🔥 When you overfeed, the osmotic pressure (salt concentration) in the root zone skyrockets. The plant absorbs too many salts and pushes them to the absolute furthest points of its vascular system—the leaf tips! The Look: The very tips of your leaves (especially the upper canopy and sugar leaves) will turn crispy, brown, and sometimes curl up. The rest of the leaf will usually be a very deep, dark, glossy green (a sign of too much Nitrogen). The Fix: If it is burn, drop your nutrient strength by 20% and give her some plain, pH-balanced water to flush out the excess salts. 💧 2. The Mechanics of a Deficiency (Starvation): 📉 Deficiencies look completely different because they usually start from the bottom of the plant or affect the veins of the leaves, not just the crispy tips. Mobile Deficiencies (Nitrogen, Phosphorus, Potassium): The plant will steal nutrients from its older, lower leaves to feed the new buds at the top. The lower fan leaves will turn entirely pale yellow and naturally drop off. 🍂 Immobile Deficiencies (Calcium/Magnesium): You will see brown, rusty spots appearing in the middle of the leaves, or yellowing between the leaf veins while the veins themselves stay dark green. The Fix: If it is a true deficiency, you simply need to gently bump up your base bloom nutrients or add a targeted supplement (like Epsom salts for Magnesium). 📈 The Golden Engineering Rule: ⚖️ When in doubt, always assume Lockout/Burn first. Overfeeding causes 90% of all flowering issues because the heavy salts physically block the roots from drinking, which makes the plant look deficient even when the soil is full of food! Check your runoff EC/PPM. If it is running extremely high, flush her. If it is super low, feed her! 🚀 Happy Growing! 💚

Lack of Cal/Mag

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Symptoms are indicating a calcium defiency with a probable lack of magnesium too. Does not look like "nute burn".

I'd wager more than one thing going on here. Definitely some imbalance in nutrition. Ca-def symptoms seen as well as some other symptoms that are less obviously attributable to anything specific. Many things can cause interveinal chlorosis. See some dark foliage, so some elements may be high. Could be lockout or just a mix of too much of some and too little of others. Limited info in diary shows poor watering habits. That would exacerbate nutritional problems if those habits continued.

Amigo, es una deficiencia de potasio K la planta requiere más K en floración, para solucionar el problema añade un poco más de lo recomendado de K potasio. Buenos humos 💨