Totally TDS
What is TDS, and what is it doing in my swimming pool? Total Dissolved Solids (TDS) in swimming pool water is the total weight of all soluble dissolved matter in the water. This includes components that exist in the water, as well as anything added to it. This includes whatever exists in your fill water and any chemicals added to the water, minerals, salts, metals, bather waste, and environmental debris that makes its way into your pool. Ideally, we want the TDS levels to be as low as possible. The general rule of thumb is to keep your TDS Levels below your starting level of 1,500 ppm. Saltwater pools and spas generally operate at higher TDS levels. This is due to salt being added to saltwater pools, higher evaporation rates, and increased chemical consumption in spas
TOTAL LOSS
High TDS levels can have a range of effects on your pool and system. These issues can include reduced sanitizer effectiveness, poor water clarity, and pool equipment damage caused by metal corrosion, scale buildup, and staining. With increasing TDS levels, there is an increased chance of galvanic corrosion. This is when there are dissimilar metals within the pool and system, which discolors the metal parts in your pool. This can be seen in the heater, on handrails and ladders, screws in the skimmer, and light niches.
IN TOTAL
How will I know when my TDS level is too high? When water is described as old, dull, or tired, it is often linked to high TDS levels. TDS is not tested with a standard test kit. There are specialty meters and test kits on the market that can test for such. In typical backyard pools, high TDS levels tend to not be an issue based on the limited bather loads they carry. Commercial pools, indoor pools, and spas tend to develop high TDS levels from greater evaporation, excessive bather loads, and more chemical use.
GRAND TOTAL
There is a saying in the pool industry that says, the solution to pollution is dilution. Industry standard for residential pools states the water should be drained and replaced at a rate of 7 gallons per bather. Residential spas are recommended to be drained, cleaned, and refilled every three months with average use and more often for heavy usage. Regular backwashing helps maintain lower TDS levels as the pool water is backwashed out, and fresh water is added. It is also encouraged for all bathers to shower before using the pool or spa.
