Ive got some brown spots

Couple of my plants have some brown spots. Getting these ready for an outside grow and on cloudy day I put them under a 90W grow light in a little box with tin foil on the sides to reflect the light. Only thing I added was topped the containers with uncle Jim’s worm castings a couple weeks back. Seeds started on 4/20

What kind of soil are they in @420guy

Potting soil from last year

They look happy and healthy IMO. Looks like they were slightly under watered at one time.