SWC method for large container
I am building a large planter (4'x4'x2'3")using 2x8 untreated pine. I am using the design from Family Handyman April issue. It has 6 - 4" flexible drain pipes at the bottom that will be filled with water. (The bottom is covered with pond liner to keep the water there) The article suggests using potting mix. I found this forum couple of days ago, so I didnt have a chance to refine my design earlier. So I want to know, what is the recommended way to create a water reservoir in such container? (I assume that SWC - self watering container?) And what kind of mix I should use for water wicking and plant nutrition?
(I already bought some vermiculite because I was looking at square foot gardening and thought I would put mel's mix in there .. Looks like I have to return it or keep it for some future garden)
Thanks .. This is my first effort at gardening and I really want it to succeed so that I don't give up! and want to get the planter ready by mother's day to move the 5-6 plants that I have already bought (tomato and herbs)