| HydroACT Features | HA2 | HA4 | HA8 |
| Sensor limit* | 2 | 4 | 8 |
| Analog output limit* | 2 | 4 | 8 |
| Relay limit* | 4 | 8 | 16 |
| Digital Input limit* | 4 | 8 | 16 |
| Isolated universal I/O | • | • | • |
| Nema 4X/IP65 | • | • | • |
| Wall & panel mount | • | • | • |
| Multilingual | • | • | • |
| High resolution display | • | • | • |
| Graphical trending | • | • | • |
| On/Off threshold control | optional | optional | optional |
| Advanced control (e.g. PID) | optional | optional | optional |
| Color display | • | • | |
| Customizable data logs | • | • | |
| MicroSD card download | • | • | |
| Remote (Internet) access | optional | optional | |
| PROFIBUS, Modbus | optional | optional |
*Sensors, I/O, and relays are all optional and must be specified at time of ordering. See specifications on back for important details.
| Sensors | Ranges | Number of Available Parameters |
| Free Chlorine | 2, 5, 10, 20, 200 mg/L | 1 (Free Cl) |
| Total Chlorine | 2, 5, 10, 20 mg/L | 1 (Total Cl) |
| Chlorine Dioxide | 0.5, 2, 5, 10, 20 mg/L | 1 (CIO2) |
| Chlorite | 2 mg/L | 1 (Chlorite) |
| Ozone | 0.2, 0.5, 2, 5, 10, 20 mg/L | 1 (O3) |
| pH with Temp | 0-14 | 2 (pH, Temperature) |
| ORP | -1999 to 1999 mV | 1 (ORP) |
| TSS/NTU | 50-4,000 NTU, 0-20 g/L | 3 (% solids, mg/L (or ppm), NTU) |
| Streaming Current | -1000 to 1000 SCV | 3 (SCV, Motor RPM, Signal Health) |
| UV254 | 0-100% UVT, 0-2 UVA | 2 (UVT, UVA) |
| Conductivity | 0-1,000 mS/cm2 | 2 (Conductivity, Temperature) |
| Torodial Conductivity | 0-2,000 mS/cm2 | 2 (Conductivity, Temperature) |
| Dissolved Oxygen | 0 to 50 mg/L 0-450% Saturation | 3 (mg/L, % Saturation, Temp) |
| Particle Counter | 2 to 100 micron | 6 (Up to 6 Size Bins – counts or ppb) |
| External Inputs | User Defined | 1 (User Defined) |