uS/cm
Conductivity
What is it
Conductivity measures how well water carries electrical current, which rises as dissolved ions increase. It is the raw measurement behind many TDS pens.
Why it matters
Conductivity is excellent for tracking stability in sensitive shrimp, soft-water fish and breeding projects. It detects mineral drift quickly even when individual tests are not run every day.
Interactions with other parameters
Conductivity responds to GH, KH, salts, fertilizers and waste ions. It does not tell you which ions are present, so pair it with targeted tests.
Ideal ranges
| Tank type | Min | Max | Unit |
|---|---|---|---|
| Tropical community | 300 | 700 | µS/cm |
| Planted high-tech | 300 | 600 | µS/cm |
| Planted low-tech | 300 | 800 | µS/cm |
| Shrimp tank | 200 | 300 | µS/cm |
Out of range: what happens
A rising trend can mean evaporation, accumulating fertilizers, heavy feeding or mineral leaching. A sudden drop can indicate too much pure-water dilution and possible osmotic stress.
Common Myths
- •Conductivity and TDS are different water contents; TDS is usually a converted estimate from conductivity.
- •Low conductivity is always natural; some species need mineral-rich water.
How to measure
Use a calibrated conductivity meter and note the unit, usually microsiemens per centimeter. Compare readings at similar temperatures or use a meter with temperature compensation.
How to adjust
Adjust it through water-change water: dilute with RO to lower it, remineralize to raise it. Make changes gradually for sensitive animals.
Pro Tips
Record conductivity after each water change to build a normal baseline for the tank.
Breeders often use conductivity because it is fast, repeatable and sensitive to small mineral changes.
