Quick Summary: Keeping the pH right is key for marijuana plants to absorb nutrients. If the pH around the roots changes a lot, it can stress the plant. This stress can cause brown spots on the leaves.
This issue is more common in hydroponic setups because the pH can change a lot. But, it can also happen in soil. It usually happens when the pH goes too high or too low.
Note: You can also see these signs from root issues or root rot!
Issue: Particular leaves on the middle or lower parts of the plant program tan or brown identifying, comparable to these images:
Option: The primary method to repair this issue is to repair the pH issue that triggered the identifying (more details listed below). The leaves that are effected will not recuperate, once you repair the problem, the issue must stop infecting other leaves.
Note: You can likewise get comparable signs from root issues!