the blue rack is one of those locker shelves, probably available in the school section. Persobally i would have liked a few more slots but i dont know how many more i could have gotten out of this box, but it would definately work if you throw it into flower sooner, possibly 2-3 weeks of veg. And the bigger box i got from walmart, i think its 22 gallons but not positive, just look for one that you think will work and get the next size bigger if possible. no such thing as to much space.

good luck man