THC Irrigation & Dryback Lab

Dryback measurement

Measurement mode

Zone / plant

Sensor / probe / plant position

Event date / time

Low/reference value

Post-irrigation / max value

Current value

Hours since last irrigation

Irrigation shot / event volume (mL)

Drain/runoff volume (mL)

Substrate volume (mL)

Irrigation event

Crop-steering phase

Feed EC (mS/cm)

Root-zone / pore-water EC (mS/cm)

Dryback target low (%)

Dryback target high (%)

Interpretation model

DrybackChange from a defined high-water reference to the later reading. Preserve the measurement method.

Shot sizeApplied irrigation volume as a percentage of substrate volume.

DrainageMeasured drainage/runoff divided by applied volume; method and collection completeness matter.

Phase mattersP0–P3 keeps overnight dryback, ramp-up, daytime maintenance and the final irrigation window separate so events are comparable.

EC contextCompare measured feed EC with root-zone/pore-water EC to see whether salts appear to be concentrating or diluting. Treat the relationship as context, not a diagnosis by itself.

User targetsDryback bands are entered by you for the crop, substrate, stage and measurement method. The tool does not present one steering percentage as universal.

Steering-phase schedule templates

Save your own daily timing boundaries and optional dryback bands for P0–P3. These templates organize a steering protocol; they are not universal irrigation recommendations and do not represent live sensor automation.

Template name

Saved template

Lights on

First irrigation / P1 start

Maintenance / P2 start

Final irrigation / P3 start

Lights off / P0 start

Auto-classify phase from event time

Phase	Your low %	Your high %	Meaning
P0			Pre-irrigation / overnight dryback
P1			Ramp-up toward your high-water reference
P2			Daytime maintenance
P3			Final irrigation to dark period

Manual schedule setup required.
Enter timing boundaries or load a saved template before automatic phase classification can run.

Field-capacity / reference profiles

Save the high-water and low/reference values you actually use for one zone, substrate, and measurement method. In weight mode the high reference should be a repeatable post-irrigation/post-drainage container state; in sensor mode preserve the same probe placement and substrate configuration. These profiles are user-defined measurement references, not universal field-capacity values.

Profile name

Saved profile

Fertigation context

Carry the current recipe and mixed-solution measurements into irrigation records so dryback events stay connected to the feed that produced them.

History filter & summary

Zone / plant

—Avg dryback %

—Avg pp/hour

—Avg shot %

—Avg drainage %

All saved zones.

Multi-sensor / position comparison

Compares the latest saved event from each sensor, probe or plant-position identifier in the selected zone. A spread can reveal spatial disagreement or method inconsistency, but it does not prove which sensor or position is correct. Compare like measurement methods, probe placement and reference definitions whenever possible.

—Latest identifiers

—Dryback spread pp

—Root EC spread

—Measurement methods

Identifier	Time	Method	Phase	Dryback	Root EC	Root-feed EC Δ

Irrigation / dryback history trend

Sensor / position

Trend metric

Save repeated events to build a trend. Dryback view overlays the user-entered target band saved with each event; root EC view can overlay feed EC.

Recent irrigation events

Time	Zone	Identifier	Steering	Event	Feed	Root EC	Dryback	Shot	Drainage

Weight mode

Use the same container, scale, plant position and reference definition. The low/reference weight is not automatically equivalent to “zero water.”

VWC mode

When using a substrate sensor, enter VWC or the sensor’s consistent water-content value directly. Compare readings only when probe placement and substrate configuration remain comparable.

Connected substrate provider

Read normalized VWC/EC telemetry through the same-origin provider gateway. Provider API keys remain server-side and are never entered into this page. The browser only performs read requests; loading telemetry updates the form and detector but never saves an irrigation event or controls hardware.

Provider

Device / sensor

Polling interval (seconds)

—provider

0mapped metrics

—latest observation

No authenticated provider loaded.
This requires the same-origin telemetry gateway to be deployed with provider credentials stored on the server.

Automatic irrigation-event candidates

When live VWC packets arrive, the browser can flag a rapid water-content rise as a possible irrigation event. This is a detection aid only: it does not know applied volume, runoff, emitter state, or whether the rise came from irrigation, probe movement, re-seating, or another disturbance.

Detect candidates from live VWC rise

Minimum VWC rise (percentage points)

Minimum time between candidates per sensor (minutes)

Maximum packet gap for rise detection (minutes)

0saved candidates

—latest VWC rise pp

—latest identifier

—latest event time

Time	Zone	Identifier	Previous VWC	Current VWC	Rise	Root EC

Detection ready.
The first packet from each sensor establishes a baseline. A later rise at or above your threshold creates a candidate after the per-sensor cooldown.