Grow tower finished with grow medium!

Aquaponics Grow Tower medium! hole punch here; Coconut Coir here; Drip tube here; After 4 months of growing with straw, I came to the conclusion that straw is not feasible as a grow medium---- I found that the straw decomposes too quickly, settles to the bottom of the tube and compacts there smothering the roots in that area. what seems to be doing best, is to have no medium,plants in a net pot or foam support,and just let the plant roots carry the water down the tube