Milwaukee MC122 PRO pH Controller Accurate, Simple & Reliable 24/7 pH Control The Milwaukee MC122 PRO pH Controller provides continuous pH monitoring and automatic control for applications where maintaining a consistent pH level is important. Ideal for aquariums, hydroponics and nutrient reservoirs, the MC122 continuously measures pH and can automatically activate connected equipment when the measured level reaches the selected set point. Simply set your desired pH level and the controller continuously monitors the system, helping take the guesswork out of maintaining stable water conditions. Key Features Continuous 24/7 pH monitoring and control Measurement range of 0.0–14.0 pH Adjustable control set point from 5.5–9.5 pH Accuracy of ±0.2 pH Easy-to-read large digital LCD display Simple 2-point manual calibration User-selectable pH set point Alarm activates when readings are above or below the set point Built-in dosing control power outlet Compatible with CO₂ dosing systems Compatible with the Milwaukee MP810 dosing pump Includes a laboratory-grade pH electrode Approximately 6.5 ft probe cable Includes mounting kit and probe holder 12 VDC power supply included Automatic pH Control The MC122 doesn't just display your current pH—it can be used to automatically control connected dosing equipment. The controller features an adjustable set point between 5.5 and 9.5 pH and a switched power outlet for controlling compatible equipment such as a CO₂ system or dosing pump. This makes the MC122 particularly useful for applications requiring consistent pH management rather than occasional manual testing. Included pH Electrode The MC122 includes the Milwaukee MA911B/2 pH electrode, featuring a gel-filled, double-junction design for dependable performance and low maintenance. Proper care and storage of the electrode are important for maintaining accurate readings and maximizing probe life. Probe Care & Storage Always keep the pH probe hydrated. Allowing a pH electrode to remain dry for extended periods can reduce sensitivity and may damage or clog the reference junction. For proper storage, use Milwaukee MA9015 pH Electrode Storage Solution. Never store the pH electrode in distilled (DI) or reverse osmosis (RO) water, as this can damage the probe. For best results, fill the probe's protective cap with storage solution, securely install the cap and store the electrode upright. Cleaning Organic residue and other contaminants can affect the sensing bulb and reference junction. For routine maintenance, Milwaukee recommends soaking the electrode in MA9016 Cleaning Solution for approximately 20 minutes. Calibration Regular calibration helps maintain accurate pH readings as the electrode naturally ages. The MC122 uses 2-point manual calibration. Calibration is also recommended after cleaning the electrode or after extended periods of storage. Specifications pH Range: 0.0–14.0 pHResolution: 0.1 pHAccuracy: ±0.2 pHSet Point Range: 5.5–9.5 pHCalibration: Manual, 2-pointAlarm: Activates when reading is higher or lower than set pointDosing Contact: 1 powered outlet for CO₂ dosing/controlIncluded Electrode: Milwaukee MA911B/2Operating Environment: 0–50°C (32–122°F), maximum 95% RHPower Supply: 12 VDC adapter includedPower Drivers: 115 VAC, 2A, 60Hz or 230 VAC, 1A, 50HzDimensions: 5.9 × 3.2 × 1.35 inWeight: 6.3 oz (meter only)Mounting Kit: Included What's Included Milwaukee MC122 PRO pH Controller, MA911B/2 pH electrode, 12 VDC power adapter, probe holder and mounting kit.
