I have two sips a full size earthbox and a full size growbox , they both hold the big 1.5 cubic feet of soil, but the earth box has a res about twice as large, so I can go further between watering at least 4 days if not more , the biggest advantage I found to the growbox was the fill Port on the front, and because you fill it on the front there is an opening with a lip on it and you can see the water level and you can see the water roots, so when you fill it you can stop before it overflows and you don't have a mess like you do with the earthbox , it was nice ditching the fill tube and the over flow port underneath