Your plants now water themselves.
HouseplantsBalconyTerraceRaised bedGreenhouseConservatoryGarden
The smart watering system with a self-learning AI: four zones continuously measure soil moisture and temperature, and each waters with its own pump exactly as much as its plants need.
- No subscription
- No account
- No internet required
The smart watering system with a self-learning AI: four zones continuously measure soil moisture and temperature, and each waters with its own pump exactly as much as its plants need.
- No subscription
- No account
- No internet required
The problem
The need changes every day. The schedule does not.
How much water a plant needs depends outdoors on sun, temperature and rain, indoors on room temperature, heating and the sunlight coming through the window. That changes from day to day.
Then there is the growth stage: a seedling needs little, a plant in full growth, in flower or bearing fruit needs many times as much, and less again as it ripens. Substrate and pot size play a part too.
A fixed schedule knows none of this and is therefore almost always off: too little on hot days and in flower, too much on cool days, after rain and for seedlings. Both cost growth. A plant only reaches its full potential with a consistently well-matched water supply.
Conventional watering timers work blind: they measure nothing, get nothing back and repeat the same routine whatever happens.
HydroCommander measures in the soil of every zone instead and waters as needed, whether the plant drinks more because of heat, heating or growth. And it checks the weather forecast itself: when rain is forecast, it skips the outdoor zones.
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Get notified on KickstarterHow it works
Measure, water, measure again, learn.
Every zone has its own digital soil sensor, developed specifically for HydroCommander, and its own pump. The sensor measures moisture and temperature continuously, right at the roots, and compensates for temperature automatically, because capacitive sensors show different moisture readings at different temperatures.
In Automatic and AI the device holds a target moisture; in Schedule it waters by the clock, with an optional Moisture check. Every zone runs independently.
Because it measures all the time, the device sees right away whether the water arrives. If the rise does not come, the Watering guard stops the zone; in Schedule it alerts you. A Daily limit, the pump timer and pump monitoring protect every zone on top.
In AI mode the device learns with every watering how fast the zone dries and how it responds to water over time, and gets timing and amount ever more precise. The target moisture comes from preset plant setups with their own value for each growth stage or from your own settings, and you can change it at any time.
Compared
Watering by the clock, or by need.
A timer always waters the same amount at the same time. When the plant needs less, on cool days or after rain, some water is left over every time: the soil gets wetter with each run until it is waterlogged. When it needs more, in the heat or while flowering, a little is missing every time, and the soil dries out step by step.
In Automatic mode, HydroCommander measures the soil moisture in every zone and only waters once it drops below the target, and only until the target is reached again. More often in the heat, less often when it is cool. That keeps the moisture in the range where the plant grows well and the soil life stays healthy. That is essential if you grow organically or in Living Soil, a living earth: microorganisms and fungi thrive best when the moisture stays even.
The five modes
Four zones, five modes, freely combined.
The mode is chosen per zone. One zone can learn while the next one runs strictly on a schedule.
How autonomous, per mode
Tap to open the mode below.
AI
A self-learning algorithm watches how fast the zone dries at different times of day and how it responds to water, and works out timing and amount from that. It keeps learning, over days and weeks, and becomes more and more precise. The target moisture comes from the plant preset or from you.
Control Device: plans timing and amount autonomously · You: set the target moisture
Automatic
You set the target, from a plant preset or yourself. When moisture drops below it, the device waters in short pump pulses with pauses in between so the water can soak in, until the target is reached again. You set the pump duration and the pause yourself.
Control Device: waters in pulses up to the target · You: target, pump duration and pause
Schedule
Fixed times and amounts, up to eight per zone. With the Moisture check, the device skips a run if the soil is still moist enough. Outdoor zones pause when rain is forecast.
Control Device: runs your schedule, with the Moisture check if you want · You: times and amounts
Manual
Watering at the push of a button, on the device or in the app.
Control You: start the watering · Device: pumps and monitors
Vacation
Predicts before you leave whether the tank will last the planned time, from the consumption of the last ten days and the planned amounts. If it will not, you find out beforehand, not on the road. Zones in harvest or rest can be skipped, and when the tank runs low, the device serves the zones you marked as important first.
Control Device: plans with the tank and supplies the important zones first · You: order and minimum level
The mode is chosen per zone. One zone can learn while the next one runs strictly on a schedule.
On the device
No phone needed.
Every mode can be set right on the touchscreen: tap a zone, switch the mode, create a schedule. Device and app stay in sync.
Features
Built safe. Thought through to the detail.
Several layers of protection make sure water only goes where it belongs. On top of that comes everything that makes life with plants easier.
Safety
- Daily limit per zoneAn adjustable maximum per zone and day. Once it is reached, watering for that zone stops.
- Pump timerEvery pump run ends after two minutes at the latest, watched by its own timer.
- Watering guardLearns per zone after how much water moisture rises, and watches the curve. If the rise does not come, it stops the zone; in Schedule it alerts you.
- Leak detectionIf the device detects a leak, the zone pauses, schedule included, until you release it or moisture rises again.
- Pump monitoringThe power draw of every pump is monitored continuously. This lets the device detect air drawn in, blocked hoses and pumps that do not start or do not switch off.
- Tank emptyFrom the calibrated flow rates the device calculates consumption, stops when the tank is empty and shows it on the display and in the app.
- Rain pauseWhen rain is forecast, outdoor zones pause. If it stays dry or the rain is not enough, the device keeps watering and holds moisture in the right range.
- After a power cutSettings and everything learned stay stored, and the device restarts on its own.
Special features
- 13 plant presetsEleven plants plus bed and several plants, with five growth stages and Living Soil, plus four of your own, fully adjustable.
- Vacation modePredicts before you leave whether the tank will last. You set a minimum level; if water runs short, what is left goes only to your most important plants.
- Weather forecastOptional forecast for your location, no account and no location access.
- Home AssistantConfigure your MQTT broker once, and the device appears in Home Assistant with all zones and further functions.
- History and exportMoisture, temperature, usage, zone and plant data for up to a year, stored only locally. Export as CSV or PDF.
- WidgetZones, plant status and tank level on your phone's home screen.
- Local, no accountDevice and app talk directly on your home network. No account, no subscription, cloud only if you want it.
- UpdatesThe device announces new firmware itself. Security updates for at least five years.
The app
Everything you can do on the device, you can do on your phone.
From first setup to analysis: setup wizard, zones and settings, schedules, pump calibration, plant presets, moisture and consumption histories and the event log.
Plus what only the app can do: 22 illustrated guides, alerts with rules you set yourself, a widget for the home screen, reports to share and the management of several devices.
Available for Android and iOS, in German, English, Spanish and French.
Live demo
The real app. In the browser. Nothing to install.
The real app runs right here in your browser, with sample data. Nothing gets installed.
No screenshots, no animation: the real application with sample data, right in the browser.
Local, not cloud
Your data never leaves your network.
HydroCommander needs no server of ours. Device and app talk to each other directly on your home network, and everything learned stays on the device.
If you want to check and control your plants from anywhere in the world, you switch the cloud on. Only then do readings and commands leave your network. Without the cloud, the device only fetches the time, once a day the word on whether an update exists, and, if you want, the weather.
What is inside
Specifications
| Zones | 4, independently controlled, each can be switched off |
| Pumps | 4 × 12 V diaphragm pumps |
| Pump monitoring | Current measurement per pump: detects an empty tank, air drawn in, a blocked hose and pumps that do not start or do not switch off |
| Flow rate | 1.7 L/min per pump with no hose attached, about 1.5 L/min with 2 m of suction and 3 m of discharge hose |
| Suction lift | up to 3 m |
| Discharge head | up to 3.5 m |
| Sensors | 4 × digital, soil moisture and temperature, RS-485/Modbus, factory-calibrated (±3%) |
| Sensor cable | 2 m, USB-C, extendable with an extension cable |
| Display | 4.3″ touchscreen |
| Modes | 5: AI, automatic, schedule, manual, vacation |
| Plant presets | 13 built in with substrate choice + 4 of your own |
| Schedules | up to 8 per zone |
| Target moisture | freely set per zone |
| Dimensions | 166 × 148 × 125 mm (W × D × H) |
| Weight | approx. 1 kg |
| Power supply | 12 V / 3 A (36 W) |
| Connections | 4 × USB-C · 5 × barrel connector 5.5 × 2.5 mm |
| In the box | Device, power supply, 4 sensors, 4 water distributors, 10 m hose, suction filter, check valve, 30 cable clips, sticker set with zone numbers, manual; drip ring and further accessories as add-ons in the configurator |
| App | Android and iOS, four languages |
| Network | home network without internet · cloud optional · no account |
Configurator
Four zones. You decide how each one is watered.
Put together your own setup here
Open the configuratorEach zone gets its watering type: a single plant with a water distributor, several plants via Y-splitters, or a bed with a drip-hose ring. In the configurator you put together, zone by zone, what should arrive at your door, and see right away what is in the box and what comes as an add-on.
Who's behind it
Hi, I'm Tobi.
Technology is my profession and my hobby at the same time. For years my own projects have been taking shape on the side, mechanical, electronic or both; I try out new processes and keep track of what is being introduced, so that nothing passes me by that could make a project better.
Apprenticeship as a machining technician, graduating among the best. Then the mechanical engineering technician specialising in design with a scholarship from the German advancement programme for gifted vocational graduates, the chamber of commerce certificates as quality manager and auditor, and the bachelor’s degree in industrial engineering, each of them alongside a full-time job in manufacturing.
After that, series development at a German premium car manufacturer: product engineer with technical team leadership, responsible for component releases, risk analyses, suppliers, deadlines and costs, up to homologation for a foreign market. Before that, six months of field data analysis at another premium OEM.
Today the lessons from every one of those stages go into my own products. What was mandatory in series development has stayed a habit here.
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Frequently asked questions
Your question isn't here?
Write to us, we reply personally. info@stemp-systems.de
Do I need a water connection?
No. Four built-in pumps draw the water from any container, even where there is no water connection.
What happens if the Wi-Fi or the power goes out?
The device waters on its own and needs neither Wi-Fi nor the app nor a server of ours to do so. If the Wi-Fi goes down, it keeps watering; only the app cannot reach it until the network is back. After a power outage it starts up by itself, and its settings and what it has learned stay stored. It then gets the time from the internet again. Without internet, you set the time on the touchscreen; until then, only the watering schedules pause. Automatic and AI mode need no clock and keep watering.
Can it cause water damage?
No watering system can rule it out completely, but the device sets several limits. Every zone has a daily maximum that Automatic, AI mode and watering schedules never exceed, and a single watering lasts two minutes at most, with a separate timer watching over that as well. If the soil moisture stops rising as usual after watering, for example because a hose has slipped off, the watering guard halts the zone; in a watering schedule it only warns. And if the container is not connected to a water line, no more can leak than it holds. One rule matters when setting up: the device always stands above the highest water level in the container, otherwise the container can drain through the device.
Do I need the app?
No. Everything the device needs for watering is set on its touchscreen, from the setup wizard to zones, modes and watering schedules to pump calibration. The app is there if you want it: for access from anywhere, the Home Assistant integration, reports, a widget on Android and several devices. Without the app the device waters according to your settings, even with no Wi-Fi at all.
Are there running costs, such as a subscription?
No. There is no subscription, no user account and no feature that costs extra: AI mode, the app, firmware updates and the Home Assistant integration come with the device. Access from anywhere through our cloud is free as well, and optional. Fixes and security updates are provided for at least five years from delivery.
What data leaves my home?
By default, readings and commands stay on your home network, what the device learns stays on the device, and there is no user account. Out of the box, only the clock sync and the daily update check of the device and the app, which sends no device ID, reach the internet. If you switch on the weather forecast, the coordinates of your location go to Open-Meteo; place search runs only when you start it, and you install updates yourself. The app has no ads and no usage analytics; only the QR scanner on Android reports usage data to Google, as Google's scanning library requires. Only when you switch on the cloud do status and commands pass through our GDPR-compliant server in Germany, over an encrypted connection. Everything else is in our privacy policy.
Does it work with my substrate?
With potting soil, garden soil, coco and peat mixes, including perlite, yes. The sensor measures capacitively and needs firm contact with the substrate all around. Loose mixes such as coco show different percentages than dense soil at the same wetness. The plant presets are tuned to potting soil, there is a separate setting for Living Soil, and you adjust the target value in small steps. AI mode also learns how fast your substrate dries and how it responds to water. The device is not made for hydroponics: it pumps only water, no nutrient solution.
Can I add fertiliser or nutrient solution to the water?
No. The device is built for clear water. Over time, fertiliser and nutrient solutions clog pumps, hoses and distributors and can damage the pumps. So fertilise by hand as usual, directly at the plants.
What is Living Soil?
Living Soil is living earth with active soil life, meaning microorganisms, fungi and worms. It is usually reused for years and fed with compost and mulch instead of liquid fertiliser. It holds water differently from ordinary potting soil and likes to stay evenly moist. That is why the Living Soil option in the presets sets the target moisture a little higher.
How many plants can one device handle?
That depends on how you use the four zones. With drip hose, one zone waters up to eight identical plants or a whole bed, tested with up to 10 m of hose. The sensor measures in one of the plants and stands for all of them, so they should be the same kind of plant. With our water distributors it is one to two plants per zone. Across four zones that makes up to 32 plants.
Indoors or outdoors?
The device always needs a sheltered spot, indoors or under a roof. From there it also waters plants outside.
Which tank do I need?
There is no requirement. The size determines how long it lasts, not whether it works; it only has to stand below the device.
When can I buy it?
Not yet. The prototype is running, and sales start with a Kickstarter campaign. Whether a production run happens depends on how many people want it.
A one-person business on Kickstarter: how safe is delivery?
Some risk remains. The prototype is in its fifth generation, firmware and app run on it in four languages, and 20 pre-series units go to testers in November 2026. For the production version we are developing our own main board and our own soil sensor: the sensor is being tested as a prototype, and the main board is designed and will be made once the campaign reaches its goal. This is the biggest risk to the schedule, so the delivery date includes a buffer: estimated November 2027, at the latest 31 December 2027. If series production or certification for your country cannot be completed by then, you can rescind the contract and get back everything you paid, including shipping. After the campaign you can cancel free of charge in the pledge manager until we notify you of shipping. And the device needs no server of ours: it keeps watering even if Stemp Systems ceased to exist.
Email updates
Whether it gets built is partly your decision.
The prototype is running, the pre-series goes to testers in November 2026, and the main board and sensor of the production version are in the works. So far every device is built individually. Whether a production run happens is decided by the number of people who sign up here.
Free and without obligation. Those on the list hear first when it starts and get their device first. We use the email address only for messages about the campaign and for your saved configuration.
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