Measurement
TDS meter
Valuable in shrimp keeping and in RO remineralising, where batch-to-batch consistency matters. Two meters using different conversion factors will disagree by up to 40 % on the same water, so compare conductivity in µS/cm rather than TDS in ppm.
Short answer
A conductivity meter that multiplies its reading by a conversion factor to report total dissolved solids. Useful for tracking change; useless for identifying which ions are present.
What it does
- Measures electrical conductivity as a proxy for dissolved ionic content
Strengths and where it fits
Strengths
- Instant reading
- Detects a leaching substrate or a failing RO membrane
- Consistency check for remineralised water
Good fit for
- Shrimp keeping
- RO water preparation
- Tracking accumulation between water changes
Limitations and where it is the wrong choice
Limitations
- Says nothing about which ions are present
- Conversion factors differ between manufacturers
- Requires occasional calibration
Poor fit for
- Replacing GH and KH tests, which measure the things that actually matter biologically