Define the measurement
Hardness concerns calcium and magnesium behavior and is often used to size and check softening. A TDS meter estimates dissolved material through conductivity. It does not identify individual substances or replace laboratory testing for a particular concern.
Use readings for the right decision
A softener can reduce hardness without sharply lowering TDS. A drinking-water membrane can change dissolved-solids readings, but that alone does not certify every contaminant claim. Ask for measurements connected to the specific equipment and desired outcome.
Keep sales demonstrations in perspective
A color change or number on a meter needs an explanation of method, units and limits. Do not accept a citywide average as the value at your home. Record untreated and treated sample points so future service can be checked with a meaningful comparison.
House, additional buildings and private-well boundaries
For a Wellington request, identify the supply serving each building before discussing equipment. A household connected to municipal water differs from a house on a private well, and a barn or irrigation line may be a separate scope. List the affected outlets and the demand the proposal is expected to serve. Do not apply a domestic equipment recommendation to animal-care or other specialist uses without the relevant professional guidance. A written line map helps the provider assess the correct project.