Hello. We have an 18ft round Coleman Vista Series II Pool. The volume said 6,092. We upgraded the pump to an intex 2800 sandfilter. I'm using the TF-100 for testing and also have an Intex automatic pool cleaner. I also use a floater and put 2 - 3 inch Chlorine tabs in it once a week. I also have an Intex Deluxe Wall Mount Surface Skimmer. This is our first pool so I'm still trying to learn as I go.