My neighbor gave me a book on soil-less gardening, so the mix I'm using is about 1/2 compost, 1/4 rice hulls, 1/4 peat moss. I guess It's possible my mix isn't homogenous enough to get proper results from the test kit. I assumed with as much compost as I used, I'd have plenty of nitrogen. But, I also don't know what I'm doing, and just following my neighbor's advice. (different neighbor than the one who possibly over/under watered.)