"A TDS number tells you whether the minerals are right"
Use the complete answer. A verdict without its boundary and next action can become another myth.
What is supported
a meter can estimate TDS from conductivity using its conversion factor.
What is not established
the display does not reveal ionic composition, separate calcium and magnesium, GH, contaminants or a species optimum.
What to do next
record meter mode and temperature basis, then measure the property the decision requires. Use the parameter guide.
Exact evidence trace
This is the selected claim-level trace, not every source used by the broader guide. Roles describe how each record is used here; they are not quality grades.
Evidence records
- limitation context Assessing the Reliability of Water-Test Kits for Use in Pond Aquaculture: Aquarium measurement tools require method-specific interpretation and cannot reveal properties they do not measure.
Supporting authorities
- Specific Conductance: Defines conductance measurement and reporting context.
- Conductivity meter manual: Shows that TDS display is derived through an instrument conversion factor.
- Hardness of Water: Separates hardness from a conductivity-derived TDS estimate.
Named open questions
- What GH, KH, pH and conductivity combinations are true biological optima? Field occurrences and study culture water describe places or reproducible conditions, not species-wide GH, KH, pH or conductivity optima.
Inspect the broader guide evidence dossier for all records, authorities, gaps, searches and changes connected to the practical guide.
Share the complete answer
Open the plain-text answer or open the original teaching card.
The detailed guide owns the evidence and limitations. Challenge this claim with a stable source if an important boundary is missing or stale.