Linda, The drain pipe is level and goes all the way through the box and has 16 inches of the bottom half removed from the middle. The pipes stick through the sides about 3 inches so if I wanted to I could join the boxes together with an 1 1/2 inch coupling and just add water to one and fill them all. I was concerned about air circulation too, that's why I used 1 1/2 inch pipe and cut the bottom half off in the middle (instead of just boring holes in the bottom of the pipe). When I removed the plants last fall, there were no signs of rotted potting mix in the pots or elsewhere, but the mix was saturated with hair like tomato roots holding it all together. I chopped it up with a hoe and plan to reuse it. Two cubic foot bags of potting mix cost about $12, and I'm cheap. By letting the reservoir get down to 1 1/2 gallons of water before you refill, it moves the saturation zone up and down about 3 inches in the pots. I think that's why it didn't rot. Rather than using the band of fertilizer as recommended by EarthBoxes, I prefer to use 12-4-8 liquid plant food (MG). I mix 1/4 teaspoon per gallon of water and it seems to work fine for tomatoes. I've only done this for a year, so please don't consider me an expert on any of this. I'm only relating my experience thus far. I agree with you about breaking up the soil, especially if mix at the bottom is rotting. I'd throw the rotted part away and add fresh mix. I switched to Scotts potting soil because all the Miracle-Gro in this area has the moisture control in it. Also, the first time you fill the reservoir, it probably wouldn't hurt to add 1/4 cup of hydrogen peroxide per gallon of water to disinfect. Hope this clears it up for you. Claud
