I've been using Sustain for the last two seasons (my first two seasons). I use the 3", the 3/4" and the extender.
Is there a more economical product to use, as I find this product expensive. I hear that the guys that work at my pool store don't use these products because of the cost and they just use a cheap liquid shock.
21 ft round above ground 10,500 gal capacity, trying to cut expenses.