Conductivity Testers

Measure the EC (electrical conductivity) of water, soil, compost, foliar sprays, etc. Theoretically, ions registered by EC meters are small & mobile enough to be available to plants. Complexed ions (large array of simple ions) will not be counted (however, if soil contains a variety of active, healthy microbes, they can break down large ion clusters).

• High quality water will have a low EC reading (<4 µS)
• High EC soils are very susceptible to nematodes
• Viability of seed germination can be determined by EC
• EC of finished compost is an indication of its quality

Note: All EC testers listed here have ATC (Auto Temperature Compensation) which removes errors caused by temperature variance. All EC testers require standard solution for proper calibration prior to testing. For those testers that don’t include standards, the solutions are sold separately.

EC is measured in micro Siemens/cm (or µS/cm) (formerly called micro mhos/cm). 1 milli Siemen/cm (mS/cm) equals 1,000 µS/cm. We simply use “µS” and “mS” here.

For conversion into “C” Salt Units: 1 “C” Salt Unit = 700 µS.

For soil EC: Plant growth depends on the quantity of mobile ions measured in soil / water extract (this measurement is also called ERGS or energy released per gram of soil). ERGS should be kept between 40 - 400 µS.

For plant tissue EC: EC of plant sap indicates the level of simple ion uptake in plants. Keep between 2,000 - 12,000 µS.

Note: On EC probe technology, the 4-Ring potentiometric probe type is more accurate & reliable throughout the entire range than the 2-Ring amperometric type. This includes D-4C, 9033EC and the Conmet 1 & 2.