A calcium deficiency causes brown patches or scorch marks on hardworking cannabis leaves. It fits very well with what we see in the pictures.
If it was more focused in the tip it might be different but the uniform browning all over is more consistent with calcium. What's not so easy is determining the root cause that led to the calcium deficiency. It's possible it's just a plain old deficiency but it really helps to understand calcium and its relationship to other nutrients and how it can effect uptake in different environments. Can help alot with diagnosis in future.
Calcium, magnesium, and potassium can exhibit antagonistic interactions, meaning high levels of one can inhibit the uptake or availability of another. For example, excessive potassium can reduce magnesium and calcium uptake, while high calcium can impact magnesium absorption. Maintaining a balanced ratio of these nutrients in soil or nutrient solutions is crucial for optimal plant growth and crop health.
Calcium uptake in plants is significantly influenced by soil moisture. In wet soils, calcium uptake can be reduced due to factors like reduced transpiration rates and potential nutrient leaching. In dry soils, low moisture can also limit calcium availability and uptake. Optimal soil moisture levels are needed for efficient calcium transport to plant roots and subsequent uptake.
Hopefully you should be able to gauge better yourself if things got a little too dry or too wet, just underneath her a little.
I copy and pasted some of that. 😀😃🙂