Total Dissolved SolidsTotal Dissolved Solids (TDS) is a measure of dissolved material in the water such as bather waste, algaecides, disinfectants, specialty chemicals, dirt & debris. High TDS can be an indication of “old” water. An acceptable TDS level is less than 2500 ppm (or less than 1500 ppm above source water). Note that these levels do not apply to pools equipped with a chlorine generator. At high TDS levels, the water can become cloudy. If the level is higher than 2500ppm, it is recommended to drain partially and refill. Do not drain without consulting your builder or service company.