Three by three

Looks to be a manganese deficiency, Leaves may become yellow in between the veins, with mottled brown spots on the affected leaves. These brown dead patches may spread and eventually kill the leaf. Leaves may also shred and fall apart. Overall growth of the marijuana plant may be stunted. With a manganese deficiency, the yellowing will begin at the base of the leaves and move outwards towards the tips. Check your ph run off to see if its in proper range . To high or to low ph will cause this problem. Hope this helps you . Good luck to you