User Guide

TDS and electrical conductivity in hydroponics
Electrical conductivity (EC) is a measurement
of the strength of the nutrient solution. The
higher the conductivity, the more dissolved
solids there are in the solution. Delicate
plants, cuttings, and seedlings can
experience fertilizer burn if the conductivity
is too high. Once the plants begin growing,
they need a stronger nutrient solution, so
conductivity must be increased by adding
concentrated nutrient. Some plants prefer a milder nutrient strength, while others grow better
and produce better quality fruit with a higher concentration.
Low conductivity implies a low nutrient concentration, which usually results in nutritional
deficiencies and slow growth rates of your plants. Basically, a higher conductivity indicates that
there is more food for your plants. However, be careful of very high levels as this can burn or
kill the plant.
If you have plant nutrient recommendations in EC units, the EC mode is convenient (see more
information about the working modes in the product manual). If your plant nutrient
recommendations are in ppm values, the TDS mode is easier to use.
Caring for your Health Metric TDS meter
● Your Health Metric TDS meter should not be submerged underwater. Only the probe
section should be immersed in water.
● The TDS meter has two metal probes and a tiny plug on the bottom of the meter. Do not
scrub or bend the probes.
● Never dip the meter into substances that can coat and damage the probes. Paint, glue,
food, and other sticky substances can damage the probes.
● Never dip the TDS meter into boiling liquids.