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Tank Management

Tanks manage your water reservoirs, nutrient solution tanks, and irrigation water containers. You record fill levels, document fillings with complete mixing recipes, and schedule maintenance tasks such as water changes and probe calibrations.


Prerequisites

  • At least one location set up (tanks are assigned to a location)
  • For EC-driven fills: nutrient plans created under Fertilization

Understanding Tank Types

Kamerplanter distinguishes five tank types:

Type Description Typical Use
Nutrient Ready-mixed nutrient solution Drip systems, hydroponics
Irrigation Treated water, pH-adjusted if needed Soil and coco grows
Reservoir Raw water storage tank Rainwater collector, RO water
Recirculation Return tank in closed systems NFT, ebb & flow
Stock Solution Concentrated A/B tanks Automated dosing

Never mix stock solutions directly

Concentrated A and B stock solutions must never come into direct contact — only when diluted with water. Kamerplanter warns you when creating stock solution tanks.

Hydroponic terms: DWC and NFT

DWC (Deep Water Culture) is a hydroponic system where the roots hang permanently in an oxygen-enriched nutrient solution — a Nutrient tank for this usually needs an air pump (see Equipment below) and regular measurement of dissolved oxygen. NFT (Nutrient Film Technique) lets a thin film of nutrient solution flow over the roots and back into a Recirculation tank — here the circulation pump matters most.


Creating a New Tank

Step 1: Navigate to Tank Overview

Click Locations in the navigation and open a site. In the Tanks tab you see all tanks for that site.

Alternatively: navigate to Locations → Tanks for a cross-site overview.

Step 2: Create a New Tank

Click Add Tank.

Step 3: Configure the Tank

Field Description Example
Name Tank label "DWC Reservoir Tent A"
Type Tank type (see above) Nutrient
Volume (L) Tank capacity 100
Material Plastic, stainless steel, glass, or IBC container Plastic
Location Which area is the tank assigned to? "Grow Tent A"
Installation Date Optional, for maintenance history 2026-03-01
Notes Free text, e.g. manufacturer notes

Equipment (optional)

When creating or editing a tank you can also toggle which equipment it has — it appears as a property chip on the detail page:

Equipment Relevance
Lid Evaporation and light protection
Air Pump Oxygenation, important for DWC
Circulation Pump Circulation, important for NFT/recirculation
Heater Constant water temperature
Light-Proof Prevents algae growth from light exposure
UV Sterilizer Reduces pathogens in the water loop
Ozone Generator Additional disinfection

If you have a sensor for fill level, EC, pH, or other water parameters in the tank, link it via Add Sensor (in the Edit tab). Current sensor values then appear in the tank detail view.

Pick a Home Assistant entity via autocomplete

In the sensor dialog, an autocomplete field suggests matching Home Assistant entities (including their current state). Selecting one automatically fills in the entity ID and, based on the entity type, suggests a metric type and sensor name. Alternatively, enter the entity ID manually (e.g. sensor.tank_ec) or link an MQTT topic.


Recording the Current Tank State

The tank state provides information on current fill level, EC, pH, and water temperature.

Enter a New Reading

  1. Open a tank.
  2. Click Record State (in the Readings tab).
  3. Enter the current values:
Parameter Description
pH Value Current pH
EC (mS/cm) Electrical conductivity of the solution
TDS (ppm) Total dissolved solids
Water Temperature (°C) Solution temperature
Fill Level (%) or Volume (L) Current fill
Dissolved Oxygen (mg/L) Oxygen content in the water — essential for root activity in hydroponics, optimal 5–8 mg/L
ORP (mV) Redox potential — an electrochemical measure of water quality, optimal 300–500 mV
  1. Save. The value appears in the state history.

Dissolved oxygen matters most in DWC

If dissolved oxygen drops below 6 mg/L, Kamerplanter warns about an increased risk of root rot for nutrient and recirculation tanks. A low ORP (below 250 mV) indicates an increased pathogen risk; values below 650 mV are considered suboptimal for disinfection effectiveness.

Regular measurements

The tank detail view shows a chart of EC and pH trends over time. Regular measurements help spot trends early — for example rising EC caused by water evaporation.


Documenting a Tank Fill

Every time the tank is filled — whether a full change, top-up, or correction — the event is recorded as an immutable entry. This lets you trace later exactly what your plants received and when.

Step 1: Record a Fill

Click Record Fill in the tank detail view (in the Fills tab).

Step 2: Select Fill Type

Type Description
Full Change Complete replacement of the solution
Top-Up Refilling evaporated water
Correction / Adjustment EC or pH correction without full change

Step 3: Enter Data

Basic values: - Volume (L) of water added - Water source (tap water, RO water, rainwater, mixed) - RO / tap water mixing ratio (if mixed, in %)

Mixing recipe (optional): Link an existing mixing recipe from your nutrient plans. This automatically imports all fertilizers and dosages.

Measurements after filling: - Measured EC after mixing - Measured pH after correction

Plan target values: If a nutrient plan is linked, Kamerplanter shows the target EC next to your actual value. You can see at a glance whether your result matches the plan.

Step 4: Save

The fill is saved in the fill history. A new tank state record with the measured values is created automatically.


Water Source Defaults

If you have configured the water source on your site (tap water EC, whether an RO system is available, etc.), Kamerplanter pre-fills base EC and mixing ratio automatically:

  1. Explicitly entered in the fill form (highest priority)
  2. From the nutrient plan (when a plan is linked)
  3. From the site water profile (from site configuration)
  4. Manual entry (when none of the above provides data)

The source of default values is shown in the form, so you always know where the pre-filled values come from.


Operator / API Functions for Tanks

The following four functions are already fully implemented in the backend, but still lack a user interface — you can currently only reach them via the REST API. They are documented here so you know they exist, in case you (or your operator) want to use them via the API or a custom script.

API only: EC Dilution Calculator

POST /tanks/{key}/ec-dilution calculates how much RO water you need to add to a tank with too-high EC to reach a target EC. Inputs: current EC, target EC, current volume (default: the tank's nominal volume), and the EC of your dilution water (default 0.02 mS/cm). The response includes the required amount of RO water, the resulting final volume, and whether the dilution is even feasible with the current tank volume.

API only: Tank Linking (feeds-from)

POST /tanks/{key}/feeds-from links a tank to a source tank it is fed from — for example a nutrient tank refilled from a larger RO reservoir. This edge is not yet shown or managed anywhere in the UI.

API only: Fill Statistics

GET /tanks/{key}/fills/stats returns aggregated metrics for a tank's fill history: number of fills by type, total volume, and average EC deviation from target.

API only: Live sensor values directly from Home Assistant

GET /tanks/{key}/states/live queries the live current state for all Home Assistant sensors linked to the tank, without saving a new tank state. A button to fetch live values in the tank detail view is planned but not yet wired to the UI — until then, see current values by regularly recording a new state (see above).


Scheduling Maintenance Tasks

Tanks need regular maintenance. Kamerplanter schedules these tasks automatically and reminds you in time.

Available Maintenance Types

Maintenance Type Typical Interval (guideline) Description
Water Change 7–14 days (DWC), 14 days (drip) Full replacement of nutrient solution
Cleaning On visible algae growth, after harvest Clean tank interior and lines
Sanitization Between growing cycles Sterile cleaning with H₂O₂ or enzymes
Calibration 7–14 days (recirculation), 14 days (nutrient tank) Calibrate the EC or pH probe with reference/buffer solution — note which probe in the notes field
Filter Change Manufacturer recommendation Pre-filter, inline filter, UV lamps
Pump Inspection Monthly Check circulation pump and pressure pump

Setting Up a Maintenance Schedule

  1. Open the tank and switch to the Maintenance tab.
  2. Click Add Maintenance Schedule.
  3. Select the maintenance type, the interval (in days), and how many days beforehand to remind you.
  4. Optionally enable "Auto-create task" — Kamerplanter then automatically creates a task when due, instead of only warning in the dashboard/tank detail view.

Recording Completed Maintenance

When you have carried out maintenance:

  1. Click Record Maintenance or tick the corresponding task.
  2. Enter date, duration, and any observations.
  3. The next maintenance date is calculated automatically.

Tank Alerts

Kamerplanter generates automatic alerts when:

  • Fill level drops below 20 % of volume (alert: "Tank almost empty")
  • pH is outside the range typical for the tank type (e.g. nutrient tank: 5.5–6.5, recirculation: 5.5–6.3, irrigation: 5.8–6.8)
  • EC exceeds the upper limit for the tank type, or deviates by more than 20 % from the assigned nutrient plan's target EC
  • pH has drifted significantly since the last fill
  • A maintenance task (water change, calibration, cleaning, …) is overdue

These alerts appear in the tank detail view and on the dashboard.


Frequently Asked Questions

How many tanks can I set up?

There is no limit. You can create as many tanks as you physically have.

Do I have to record every watering as a tank fill?

No. Tank fills are for filling and changing the tank. Individual watering events are recorded in the Watering Log — either via a planting run or directly through the Watering Log menu item.

How do I calibrate a pH probe properly?

Rinse the probe with distilled water first. Immerse it in a buffer solution with a known pH (e.g. pH 7.0). If the displayed value deviates, adjust the calibration offset accordingly. Repeat with a second buffer solution (e.g. pH 4.0). Record the calibration as a maintenance entry.

What is the difference between tank EC and plant substrate EC?

Tank EC shows the concentration of the stock solution. Substrate runoff EC shows how much salt has accumulated in the root zone. Both values matter, but they measure different things.


See Also