ppm
TDS
What is it
TDS estimates total dissolved solids from electrical conductivity. It is a quick snapshot of how much dissolved material is in the water, not a direct list of which minerals are present.
Why it matters
TDS helps keep shrimp systems, RO remineralization and water-change routines consistent. A sudden rise can reveal evaporation, overdosing, waste buildup or source-water changes.
Interactions with other parameters
TDS includes GH, KH, fertilizers, sodium, nitrate and many other ions. Pair it with GH and KH tests to understand what is actually changing.
Ideal ranges
| Tank type | Min | Max | Unit |
|---|---|---|---|
| Tropical community | 150 | 350 | ppm |
| Planted high-tech | 150 | 300 | ppm |
| Planted low-tech | 150 | 400 | ppm |
| Shrimp tank | 120 | 200 | ppm |
Out of range: what happens
Very low TDS may mean insufficient minerals for shrimp, snails or hard-water fish. Very high TDS can stress soft-water species and make acclimation harder.
Common Myths
- •TDS tells you water quality; it only tells you total dissolved load.
- •A specific TDS guarantees shrimp success; the mineral recipe matters too.
How to measure
Use a calibrated TDS pen and rinse it after use. Remember that evaporation raises TDS because water leaves but dissolved solids stay.
How to adjust
Lower TDS with RO dilution and regular water changes. Raise it with a remineralizer matched to the livestock instead of random salts.
Pro Tips
Use TDS to match new water to the tank before water changes in shrimp aquariums.
Top off evaporation with pure water, not mineralized water, unless you intentionally need to raise TDS.
