Your garden is excellent but ... on your next grow I would try to build a reflective wall around the plants .... possibly one that you can move a section at a time for access ... I use a lot of 1/8" particle board that is white on one side and Masonite on the other for containing my light w/ reflectivity ... it's hard to imagine a more successful grow than what you've got going but utilizing the lost light would make a difference .... you can also use simple Masonite covered on one side w/ either Mylar or tin foil shiny side out ... I have used tin foil for ever ... used Mylar briefly and like it but it's a b.tch to put up alone ...