YieldPivot

Reservoir trend

Read EC direction together with water-level direction.

EC rising or falling is not a diagnosis by itself. Pair the verified reading with actual reservoir volume, source water, recent additions, crop stage, temperature, and time so the next action fits the tank you have.

Reviewed August 30, 2026

Why the pair matters

Plants can take up water and dissolved nutrients at different rates. Evaporation removes water while leaving dissolved salts. Top offs add water and its own dissolved material. These processes can move water level and EC in different directions, but the direction only narrows the questions to check.

A short interval, a small reservoir, a recent dose, a leak, or a poorly mixed sample can distort the apparent trend. Confirm the meter and units using the EC meter guide before changing the reservoir.

Build comparable observations

Mark or measure a consistent working volume rather than estimating from container capacity. Take readings at a similar time, after normal circulation, away from fresh additions. Record EC, water level, temperature, crop stage, top offs, feeds, and pH corrections.

One reading describes a moment. A sequence taken under repeatable conditions is stronger evidence. Remeasure any surprising value after checking probe cleanliness, unit, bubbles, circulation, and source-water contribution.

EC and water-level interpretation table

This table is a decision aid, not a diagnosis. Confirm the reading, units, water level, sampling conditions, and recent reservoir history before acting.

Four observation patterns and the next evidence to collect
Observed patternPossible context to checkMeasured next step
Water level down, EC upWater loss may have concentrated the solution, but leaks, heat, source water, and sampling differences can contribute.Verify the working volume and EC, review top-offs, then restore known water only if that fits the operating plan; circulate and remeasure.
Water level down, EC downNutrient uptake is one possibility; meter drift, a low-EC top-off, or inconsistent samples can look similar.Check the meter, crop condition, stage, and addition log. Do not automatically add fertilizer from direction alone.
Water level stable, EC changesRecent nutrient or pH products, precipitation, temperature, measurement error, or selective uptake may matter.Verify volume and mixing, inspect deposits, review every addition, and repeat the reading under comparable conditions.
Water level and EC stableThe current routine may be steady, but EC cannot prove balanced nutrient composition or healthy roots.Continue scheduled observations and inspect the crop, roots, solution, and equipment.

Top off deliberately

Know the source-water EC, alkalinity, hardness, sodium, chloride, and treatment path where relevant. A top off changes both volume and chemistry. Add a measured amount, circulate fully, and remeasure. Do not assume source water is a zero-EC diluent.

See source water for hydroponics for the limits of EC alone. If the tank has accumulated many corrections, the math may be less trustworthy than a documented fresh mix.

Separate correction from diagnosis

If verified EC is below a product or crop plan's target and a nutrient increase is appropriate, calculate from current EC and actual working volume. Use the selected single product or multi-product recipe according to its label and known product mapping.

Add a conservative first stage, dissolve, circulate, remeasure, and recalculate. Do not blindly add the original remainder. If EC is above target or no increase is required, nutrient addition is not the answer; use the reservoir decision guide.

Turn the current state into a measured next step

YieldPivot calculates from the current mixed-reservoir reading and working volume. It does not infer crop health from the trend. Confirm the product or recipe, preserve its component relationship, measure each amount, circulate, and decide again from the new reading.

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