The Blumat Digital takes the guesswork out of watering by measuring soil water tension directly in the root zone. The surface of a large pot can appear dry while the lower root zone remains wet—or the surface may still feel moist while the deeper soil is already drying. The Blumat Digital remains installed near the roots, allowing you to check conditions below the surface without lifting the pot, digging into the soil or relying entirely on appearance. Unlike inexpensive electronic probes that estimate moisture from electrical conductivity, the Blumat Digital operates on the tensiometer principle. Its water-filled tube and porous ceramic tip measure how strongly water is being held by the surrounding soil. The display reports this tension in millibars: Lower reading: wetter soil; water is easier for roots to extract Higher reading: drier soil; roots must exert more force to extract water The Blumat Digital measures moisture but does not automatically control irrigation. It is ideal for establishing a consistent watering routine, comparing moisture at different depths and determining how quickly a container dries under changing seasonal conditions. Why Measure Soil Water Tension? A tensiometer does not simply tell you that water is present. It indicates how available that water is to the plant. This makes the Blumat Digital particularly useful for: large indoor and outdoor containers valuable specimen plants shrubs, hedges and raised beds greenhouses and commercial nurseries overwintered plants that require less frequent irrigation comparing different soils or irrigation schedules determining whether water has reached the deeper root zone reducing unnecessary watering based only on a dry-looking surface Soil-water-tension readings are specific to the plant, soil or growing medium, root-zone depth and environmental conditions. Rather than relying on one universal number, monitor the plant and establish the reading at which it normally requires water. Permanent Root-Zone Monitoring The Blumat Digital works best when left installed in one representative location. This allows readings to be compared consistently over time. For very large containers, beds or unevenly watered areas, more than one sensor location may be useful. A single reading describes conditions near the ceramic tip and may not represent every part of a large root zone. After watering, watch how quickly the reading falls and whether moisture reaches the sensor depth. If the reading changes very little, the irrigation may not have penetrated deeply enough. A reading that remains extremely low for a long period can indicate that the root zone is staying wetter than intended. Installation Instructions Unscrew the digital measuring head from the plastic tube. Soak the plastic tube and ceramic tip in water for at least 15 minutes. Do not immerse the unscrewed digital measuring head. Fill the plastic tube completely with tap water, right to the brim. Screw the measuring head back onto the tube as far as it will go. Insert the ceramic tip into the active root zone. Blumat recommends installing it approximately 15–18 cm deep and, in a container, approximately 5–8 cm from the edge of the pot. Ensure the ceramic tip is in close contact with the surrounding soil. Air gaps can interfere with the measurement. Allow approximately two to three hours for the sensor to stabilize before relying on the first reading. For newly potted plants, gently rotate the sensor clockwise into the loose soil and lightly firm the soil around it. For dense, hard or heavily rooted soil, do not force the ceramic tip into place. Make a suitably shaped hole first, add loose moist soil around the installation area, insert the sensor and gently firm the soil around it. Taking a Reading Briefly press the button. The current soil-water-tension reading will appear for approximately 10 seconds and will be displayed in millibars, or mbar. Interpreting the Reading A reading close to 0 mbar indicates very wet or nearly saturated conditions. As the soil dries, the number rises because the remaining water is being held more tightly by the soil. There is no single ideal reading for every plant or growing medium. Suitable irrigation thresholds vary according to: plant species growth stage soil texture and composition container size sensor depth root development temperature, light and airflow the amount of drying the crop can tolerate Use the meter to establish a repeatable range for your particular plant and soil. Note the reading when the plant is fully watered, monitor how it changes as the container dries and record the reading just before the plant would normally begin showing water stress. Water before the plant reaches that stress point, then observe whether the reading falls after irrigation. Over time, this creates a practical watering threshold based on your own growing conditions rather than a generic schedule. Resetting the Blumat Digital Reset the calibration if the display begins showing readings that are clearly impossible or inconsistent. Remove the measuring head from the plastic tube. Press and hold the button for approximately five seconds. Continue holding until “ooo” appears on the display. Refill the plastic tube completely with water. Reattach the measuring head. Reinstall the sensor and allow two to three hours for the reading to stabilize. Maintenance and Care The Blumat Digital slowly loses water during normal operation. Check the water level periodically through the translucent casing. Blumat recommends refilling it when the tube is approximately half full; under typical use, this may be necessary once or twice per year. The measuring head is splash-resistant from above but is not waterproof or airtight. Avoid directing irrigation water onto the display, and never submerge the measuring head. A protective cap may be used where direct watering cannot be avoided. Product Details Professional root-zone soil-moisture measuring instrument Uses the tensiometer principle Displays soil water tension in millibars Low reading indicates wetter soil High reading indicates drier soil Intended for permanent installation in one monitoring location Suitable for indoor and outdoor use Works in soils and clay granulates Does not automatically control irrigation Includes one Blumat Digital sensor and operating instructions Manufacturer product number: 50205 IncrediGrow SKU: 210000006244
