Why automate watering
Tray mode
Larger installations need a different approach. This walkthrough shows PotWatch in tray mode, looking after forty-one plants in an L-shaped planter from a single controller.
The L-shaped planter
From above, this is an L-shaped planter in a foyer. Each arm holds a row of twenty matching plants, and a large feature plant stands in the corner. Everything that keeps them watered is hidden inside.
Watering from below
In the two arms, water doesn't need to go into every pot. The plants have fully established roots that have grown down through their drainage holes. So PotWatch fills the tray beneath them, and the plants draw up what they need. The tray is then left to dry out before it is filled again, so the roots get a wet and dry cycle rather than sitting in water.
Inside the planter
Two trays
Each arm has its own long tray, running under all twenty pots. Tray A is under one arm and tray B is under the other, so each arm is watered on its own schedule.
Established roots
The plants stay in their standard nursery pots. Once established, their roots grow through the drainage holes and reach into the tray, where they take up water.
One sensor per tray
Each tray has a single water level sensor, at the far end from where the water comes in. The red mark is the low level and the green mark is the fill target. When the far end reaches target, the whole tray is full.
Corner feature plant
The large corner plant is watered from the top, just like the tanball, with its own drip line and its own saucer sensor.
Reservoir
The reservoir runs the full length of both arms, under the trays, and on under the corner. It holds weeks of water for all forty-one plants. The pumps and the controller sit at the corner, where a technician can reach them.
Three pumps
Three small pumps sit in the reservoir: one for tray A, one for tray B, and one for the corner plant.
Drip lines
Each tray has a drip line along its length, with outlets spaced out so the tray fills evenly from end to end.
One controller
One three-channel controller runs it all. Channel one is tray A, channel two is tray B, and channel three is the corner plant. Each tray channel has a tray setting: a fill amount sized to that tray. A built-in IoT SIM reports to the online portal.
Battery
A rechargeable battery powers the controller, the sensors and all three pumps. It is designed to last well over a year between charges, and recharges through a USB-C port.
Temperature sensor
A temperature sensor in the reservoir reports the water temperature, so you can spot water that is too cold or too warm for the roots.
Fill port
The reservoir is refilled through a fill port in the corner, without moving any plants.
The watering cycle
Every channel is checked
Four times a day, the controller reads both tray sensors and the corner saucer. This morning, tray A has dried out below the low mark, and so has the corner saucer. Tray B still has water.
Tray A is filled
So pump one runs for tray A's setting, an amount sized to the tray, not to each pot. Pump three waters the corner plant from the top. Pump two stays off.
Water spreads along the tray
The water spreads along tray A until the far end reaches the fill line. The roots in the tray start drawing it up.
Level confirmed
The sensors read again. Tray A is at target, and so is the corner saucer, so every pump stays off.
One report
One report goes to the portal, covering both trays, the corner plant, the reservoir level and the water temperature.
Days pass
Over the following days, the plants drink the tray down. Once the tray is dry, it stays dry until a later check, so the roots dry back between drinks. Then it is filled again. Each arm runs on its own schedule, because one side may get more sun or air-conditioning than the other.
Refill alert
Weeks later, the reservoir runs low. When a pump can no longer bring its tray back to target, the controller raises one alert for the whole planter.
Refill
A technician refills the reservoir through the corner fill port during a regular tidy-up visit. The alert clears, and both trays are filled again.
Close
Forty-one plants, two trays and one controller. Tray mode lets PotWatch look after large installations, with fewer visits and a record of every watering.
