Total Dissolved Solids (TDS) Explained
TDS is the one water-chemistry number that can't be corrected with a chemical, which is exactly why it gets ignored until it's a real problem. This site is dedicated to a single build method: gunite (shotcrete) construction, rebar cage, sprayed and hand-finished concrete, engineered bond beams, and a design that can be shaped to anything the lot allows, from tanning ledges to negative edges to integrated spas.
What's Actually Dissolved in There
Total dissolved solids is a measure of everything dissolved in the water that isn't water: dissolved minerals, salt (if using a salt system), and the residue left behind by every chemical ever added. It climbs steadily over a pool's life simply from normal use and treatment, there's no way to "use up" TDS the way chlorine gets consumed.
Why High TDS Matters
Once TDS gets high enough (often cited around 2,500-3,000 ppm for non-salt pools, higher for salt pools since salt itself counts as TDS), water can start to look dull or cloudy even with correct sanitizer and pH, and chemicals generally become less efficient in saturated water. The only real fix at that point is a partial drain-and-refill to dilute the water back down, there's no additive that lowers TDS.
Where This Fits
See our Pool Repair service page, or Financing if cost is the next question.
Related Reading
pH and Alkalinity Basics for Pool Owners
Why alkalinity is the buffer behind pH, and how to adjust each one without chasing the other in circles.
Pool Chemical Balancing Explained
What sanitizer, pH, alkalinity, and calcium hardness actually do, and why getting one wrong throws off the rest.
Pool Stain Identification and Removal
How to tell metal stains from organic stains from scale, and what actually removes each type.
Get a Free Quote
Tell us about your project and we’ll follow up within one business day.