Softening equipment primarily addresses hardness. Hardness tests and TDS meter readings cannot replace each other. Resin, control valves, brine tanks, and regeneration drainage must be checked together.
Hardness and TDS answer different questions
Sodium-cycle ion-exchange softening primarily exchanges calcium and magnesium ions in water. TDS describes total dissolved solids; common TDS meters estimate readings from electrical conductivity. A change in TDS before and after softening does not alone prove whether hardness meets downstream requirements. The appropriate hardness test method, units, and sampling location are needed.
The control valve is not the exchange medium
Resin performs ion exchange, while the control valve switches flow paths according to its program. The tank, distributor, resin, brine tank, brine draw, and drainage provisions work together during operation. Changing valve timing alone cannot replace checks of raw water, resin condition, and regeneration conditions. Record the corresponding model, program version, and site connections.
Regeneration arrangements depend on the conditions
Record raw-water hardness, consumption, operating hours, the regeneration process, and tests after regeneration. Both time-based and volume-based control need settings supported by the current system's conditions. Confirm salt requirements using the specific equipment and resin instructions. A generic “salt-saving percentage” or a fixed number of days cannot replace an actual assessment.
Documents to prepare
| Item to check | Information or records | Confirm the application |
|---|---|---|
| Water quality | Raw-water and softened-water hardness, and test method | Check the treatment target |
| Supporting system | Models of the resin, valve, tank, and brine tank | Check the complete system |
| Regeneration | Consumption, settings version, timing, and testing | Track changes |
Related resources
- Buying or replacing softening resin: hardness requirements and regeneration records
- Selection, procurement and maintenance resources
- Contact Gudian to check the requirements for this inquiry
Knowledge compiled by Gudian Technology, with AI-assisted editing and completed content review, October 7, 2026. This content supports requirements preparation and document checks. Confirm specific models, operation, acceptance, supply, and services using the corresponding documents and project conditions.