After seedlings are up they require a smaller dose of fertilizer than what would be applied in the garden. The MGC Book, on page 183 calls for the mixing of 1 ounce of the weekly feed fertilizer to 3 gallons of water. It also calls for a sprinkling can to be used for its application.
An old laundry detergent bucket was washed out and used to hold our constant feed mix. A measured 3 gallons of water was poured into the bucket and then the water line marked on the outside of the bucket with a marker.
A sprinkling can is simply a can with holes made with a small nail and hammer. For our own use here at home we took an empty 16 ounce can of green beans and made the holes in the bottom with a small nail.