Anybody knows what this is? Spots on leaves

hello dave I like to grow in organic soil and I also use biobizz, bioheaven. If I may, I have 2 tips for you. First, never let it dry too much to avoid the risk of burning. second, use a percentage of organic soil with substrate, I like to work with 30% organic matter. With this you can use and make better use of Biobizz's organic nutrients, good harvests

Id say water a little bit calmag just as the people previously told, but if its only this one leaf its really no big problem

It looks like a calcium deficiency unless those are the bottom leaves and they were getting sprayed with water then they could just be burnt but I'm leaning towards calcium deficiency. I would start some cal mag or work some oyster shells into the top layer of soil. Hope this helps

It looks more like a potassium deficiency with discoloration and spots. I would check your substrate ph first and foremost.

I wont care, because its an old leaf from the Bottom, you can not expect that she stays fresh and green from day one to harvest, its very normal, you are only in trouble if all your leaves look like this

Look like Calmag deficient. Although the rest don't show it. So I would assume it to be a leaf that got water ok it and caused it to have brown spots? That would be the best bet. Since the others don't show anything wrong. Please consider me as the answer so I can be entered for a chance to win grower of the month contest 🙏 please and thank you 😃 I would really appreciate it growmie.