All this stuff is an expensive initial outlay, what with the test kit, a speedstir, extra reagents, but when compared to the fact that I was spending around $50 a week and sometimes a lot more, all of last summer when I got a water clarity / algae issue and the pool store kept loading me up with phosphate removers, clarifiers, flocculents, stabiliser, powdered shock time after time. It really doesn't take long for self testing to become the cheaper option. I wish I had started out this way!