16,000 gallon in-ground vinyl-liner pool. Water source is a private community well. Jacuzzi sand filter, Laser L250. Primary pump has been ORUM 1 1/2 HP. Just added Lorentz PS2-600 solar pump which begins running with first light. Have been using Aquacheck 7 test strips. Waiting for delivery of TF-100 and CYA test kit.