HM Digital CIC-152 Review: The Best Dual TDS/EC Controller for Dosing & Injection Systems
If you're managing a water treatment system, hydroponic setup, aquaculture operation, or laboratory environment, precise TDS and EC control isn't optional — it's critical. The HM Digital CIC-152 is a professional-grade inline controller built to monitor and automate dosing and injection systems with pinpoint accuracy.
In this review, we'll break down everything you need to know about the CIC-152-N and CIC-152-4 models, who they're built for, and why they're one of the most reliable TDS/EC controllers on the market.
What Is the HM Digital CIC-152?
The CIC-152 is a dual-channel inline TDS/EC controller that continuously monitors water quality and automatically activates connected devices — such as pumps, valves, or dosing systems — when TDS or EC levels fall outside your defined range. Unlike handheld meters, the CIC-152 is designed for continuous, automated control in live systems.
It comes in two variants:
- CIC-152-N — Uses the NaCl conversion factor (avg. 0.5), ideal for general water treatment and drinking water applications. TDS range: 0–5000 ppm.
- CIC-152-4 — Uses the 442™ conversion factor (0.4–0.7), preferred for hydroponics and professional lab use. TDS range: 0–8500 ppm.
Key Features
- Dual-channel control: Manages two independent devices simultaneously (e.g., a pump and a valve)
- Tri-color LED display: Green (in range), yellow (approaching limit), red (out of range) — instant visual status at a glance
- Two adjustable set points: Define your maximum and minimum TDS/EC thresholds independently
- Two independent alarms: Set alarm thresholds separately from control points for early warning
- Relay switching: 5A, 250VAC dry contact relay — compatible with most pumps and solenoid valves
- Automatic Temperature Compensation (ATC): Accurate readings from 1–80°C (33–176°F)
- Digital push-button calibration: Factory calibrated at 1413 µS; easy field recalibration
- On-screen temperature display
- Includes SP-1-PSC probe: 1/2″ NPT bushing with 3m (9.8 ft) shielded cable
Technical Specifications
- EC Range: 0–9999 µS
- Accuracy: ±2% of reading
- Resolution: 0.1 ppm (0–999) | 1 ppm (1000–9999)
- Relay: Open/closed dry contacts, 5A 250VAC
- Power: AC 110V / AC 220V
- Dimensions: 7.2 × 7.2 × 11.1 cm (2.8 × 2.8 × 4.4 in)
- Weight: 241 g (8.5 oz) | Shipping: 610 g (1 lb 5.5 oz)
- Country of Origin: South Korea
Who Should Use the CIC-152?
The CIC-152 is purpose-built for applications where water quality directly impacts outcomes:
- Hydroponics & aquaponics: Maintain precise nutrient concentration for optimal plant growth
- Water treatment facilities: Automate dosing to keep treated water within compliance thresholds
- Aquaculture: Protect fish and aquatic life from TDS/EC fluctuations
- Laboratories: Ensure consistent water quality for experiments and equipment
- Commercial RO systems: Trigger flush or bypass valves when TDS exceeds limits
CIC-152-N vs CIC-152-4: Which Model Do You Need?
The only difference between the two models is the conversion factor used to calculate TDS from EC:
- Choose CIC-152-N if you're working with sodium chloride (NaCl)-based solutions or general municipal water
- Choose CIC-152-4 if you're working with hydroponic nutrient solutions or need the wider 0–8500 ppm range
When in doubt, the CIC-152-4 offers greater range and flexibility for professional applications.
Final Verdict
The HM Digital CIC-152 delivers industrial-grade TDS/EC control in a compact, easy-to-install package. With dual-channel relay control, independent alarms, ATC, and digital calibration, it's one of the most capable inline controllers available at this price point. Whether you're running a hydroponic farm, a water treatment system, or a lab, the CIC-152 removes the guesswork and automates water quality management reliably.