The AC Infinity AI Soil Sensor is a moisture and saturation probe for the Controller AI+. It reads what is happening at the roots once a second and hands that to the controller, so watering can run on the actual state of the medium rather than a schedule and a guess. The stem detaches for deeper placement and the whole thing is IP67-sealed against water and dirt.
Water on what the medium is doing
Lifting the pot tells you something. It tells you less in a fabric pot, less again in a coco run, and nothing at all while you are at work. The soil sensor gives the controller a live moisture figure, which turns watering into a trigger like any other: below a set saturation, the controller runs a pump or opens a valve through a UIS Control Plug, and stops when the number comes back up.
Even without automation, the log is worth having. A fortnight of saturation data shows you how fast your medium actually dries down, which is the fastest way to work out whether your watering interval is right and where the dry-back is happening.
Built to live in the pot
The stem is fibreglass, marked with depth measurements, and detaches so you can seat the sensing element properly rather than perching it in the top few centimetres where readings swing with every surface watering. The IP67 seal and stem cap mean it survives being in wet medium permanently, and the probe profile is designed to slide between roots rather than cut through them — fabric pots, beds, potting mixes and garden soil all work.
Specifications
| Product identification | |
| Manufacturer | AC Infinity Inc. |
| Product name | Soil Sensor for Controller AI+ |
| Model | AC-SLS3 |
| UPC | 819137024755 |
| Dimensions | |
| Sensor dimensions | 3.6 × 7.2 × 1.4 cm (1.41 × 2.83 × 0.55 in) |
| Cord length | 3.66 m (12 ft) |
| Performance and technical | |
| Detection | Moisture, saturation |
| Refresh rate | 1 second |
| Accuracy | ±5% |
| Material | Fibreglass stem, detachable |
| Water resistance | IP67 |
| Compatibility | Controller AI+ (AI sensor port) |
| Documentation | |
| Quick start guide | |
FAQ
What controller do I need?
The Controller AI+. The AI sensor range plugs into its sensor ports, which the Controller 69 Pro and Pro+ do not have.
Can I run one sensor per pot?
Not today — one soil sensor per controller. In practice you pick a representative pot: same size, same medium, same position relative to the light and the fan as the rest, and preferably one of the drier ones so you are not overwatering the others. Most people place it in whichever pot dries out first.
Does it work in coco or rockwool?
It reads moisture and saturation in any medium you can push the probe into, so coco and soil mixes are fine. Rockwool slabs and very fine media are harder to place well because the probe needs consistent contact, and a poorly seated probe reads air rather than medium. Push it in fully, seat it away from the drip point, and let the readings settle for a day before you build a program on them.
How do I make it actually water the plants?
The sensor reads, the controller decides, and a device does the work. A pump or solenoid on a UIS Control Plug is the usual arrangement — the plug switches its power on and off to the controller's program. Anything that starts running by itself when it receives power will work.
Can I leave it in permanently?
Yes — the IP67 rating and stem cap are there for that. Rinse the probe when you repot and check the stem is still fully seated after any big disturbance to the medium.