i started a small hydroponic system in my greenhouse with an 18 gal tub following a youtube video the system has 12 net pots with half tomatoes (early girl) and half with strawberry’s. the strawberry’s are loving the system but the lower leaves on some of the tomatoes are turning a lite yellow with a pale purple tint what’s wrong with them? Could i have over done the nutrients? Or is it just some disease that followed the plants from the store?