Bobbie,
I do hope you are going to use the "3:2:1 Combo Mix", or something close to it. You will get far better results with this aerated Combo Mix than with Potting Mix alone. See the EarthTainer III Construction Guide for the specific recipe.
Regarding naming your design, you could call it The "BobbiTainer" - - oops, didn't she do something really bad to her husband a few years ago?
Raybo
p.s. If you can't get Tomato-tone in Point-N-Shoot Texas, you can get it on Amazon for $9.99 per 4 lb. bag. Shipping free when you make a total purchase of $25.00
http://www.amazon.com/Tomato-Tone-4-...0034960&sr=8-1
p.p.s. Also just found another link for the 20 lb. bag of Tomato-tone for $26.50 including shipping, which is a much better deal if you need that much.
http://www.amazon.com/Espoma-Company...0037795&sr=8-1