Zkittlez #2 in the Sanlight

This lady is doing fine, buds are swelling nicely. Bud she also is showing similar symptoms like her sister: Some lower leaves are becoming yellow or brown almost overnight. Luckily it affects only a few and does not cause any problems, but it seems there is something with my setup this strain does not like. No idea what it is. I'm sure it is not overwatering as the soil is bone dry every day and I'm extra careful not to give too much water. No runoff at all every time. She will need one or two weeks longer as I'm gradually removing light hours in order to force the gorilla into flower.