1 To test pool water you all need to prepare a 1.5 PPM chlorine gas solution 2 Whether your chlorine level is 1.5 ppm or not (whether or not you find a calibration point), use a traditional test strip 3 Once your calibration is happy with you, you do not need to recalibrate it unless you change your pool measurements with different pool water . Summary Design of the risepro tester for domestic scale pools or spa (industrial or non-salt pools) Once successful calibration, you can quickly and easily test chlorine and acid levels and basic pool water. So there is no need for a more complex and confusing "traditional liquid chlorate basic kit"! With this handy tester you can quickly test your chlorine and pH in the ideal range of 7.8: chlorine 1.2 1.7 PPM, pH 7.2. If your test results exceed this range, provide you with useful information on adaptation to chlorine and acid - base in the corresponding pool. It is a great tool you may need to maintain swimming pool water. Specifications Recommended chlorine levels for pools and spas are 1.2, 1.7 PPM Recommended pool pH and Spa levels are 7.2 and 7.8 respectively Size (cm) Main unit: 190 x 120 mm Probe with handle: 150 mm length Probe (piece): 48mm long (Black Strap not available) Cable (root): 130mm long Power supply: 1 AA 1.5 V alkaline battery Weight: 160 G (not included in battery) Contains 1 x pH, Cl2 tester, probe 1 instruction manual