NUTRIENT pH AND ECSource-led notes · UK English
WaterMeasureWaterMeasureSOURCE NOTES, NO ORIGINAL READINGS

THE TANK NOTES

Nutrient-solution notes

What published sources say pH and EC can show in a hydroponic reservoir, and what they still are not.

Reviewed

What do pH and EC tell you in a nutrient solution, and what do they not?

In a hydroponic reservoir, pH describes acid–base state and EC describes conductivity. Science in Hydroponics reported 50 nutrient-salt combinations and also compared solutions near the same EC that still differed in ion identity. A displayed ppm is not the mass of a target nutrient. These pages attribute those experiments to their author. WaterMeasure has not published an original series.

NoteComparison it keeps
pH and ECAcid–base state versus conductivity
TDS is a factor500, 600 and 700 scales versus raw EC
What ATC correctsElectrode compensation versus the sample’s own chemistry
Probe immersionA handheld dip versus continuous immersion

Which notes are in this edition, and whose measurements are they?

This edition has four source notes: pH and EC, the TDS factor, what ATC corrects, and handheld dips versus continuous immersion. Each one names the publication it cites and states the limit of that citation. The cards below are those notes. They are not results tables, and the blank records do not contain readings.

Still-life of a nutrient reservoir, a handheld probe with an unused display, and a blank log sheet.
Explanatory still-life of the log ingredients. Not a WaterMeasure test.
Two small beakers of the same pale nutrient solution, one with a pH electrode and one with a conductivity probe. The meter displays are blank or showing unused segments.Source-based note

What pH and EC tell you in a nutrient solution

pH is an acid–base state. EC is a conductivity. Published hydroponic experiments keep those two readings apart, and they do not name individual nutrients.

8 MIN READ One beaker of nutrient solution beside a handheld meter whose display is blank or showing unused segments, and three small empty vials.Source-based note

TDS on a meter is EC times a factor

Portable meters usually display ppm as conductivity multiplied by 500, 600 or 700. That number is not a drinking-water safety decision.

7 MIN READ A beaker of nutrient solution in a shallow water bath with an analog thermometer and a probe whose display is blank or showing unused segments.Source-based note

What ATC corrects — and what temperature still changes

Automatic temperature compensation adjusts an electrode slope or a conductivity coefficient. It does not turn the sample into its chemistry at 25 °C.

7 MIN READ A dry handheld probe on a folded cloth beside a similar probe standing in a small nutrient reservoir. The displays are blank or showing unused segments.Source-based note

Handheld dips and continuous immersion are different jobs

A waterproof handheld probe is not automatically a probe that the maker allows to stay in the tank. Handbooks for the related retail models have not been checked.

7 MIN READ