How are Total Dissolved Solids Tested?
It is always a good idea to test the TDS at least once a month in pools, even more frequently in spas, and most importantly, whenever there is a problem. For proper swimming pool and spa maintenance, NSPI suggests the following operational guideline levels for TDS: 300 ppm – minimum, 1000-2000 ppm – ideal, 3000 ppm – maximum, or 1500 ppm maximum at pool startup. Pools with salt generators can generally maintain a slightly higher level. The primary component of TDS in these pools is sodium chloride, which is very soluble. There are two ways to measure TDS levels. A portable conductivity meter is one common method. TDS meters measure conductivity of certain species in a sample and then use factors to compute guideline TDS ppm values. These instruments require periodic calibration to maintain accuracy. As an alternative to the conductivity meter, an inexpensive, dip-and-read test strip has been recently introduced that allows you to obtain TDS readings. You simply compare the reacted colo
