Your shopping cart is currently empty.
*Free MA955 solenoid valve will be added to your order automatically after you finish your purchase.
Milwaukee MC122 pH Controller with Electrode – Continuous pH Monitoring & Control Made Easy
Take the guesswork out of pH regulation with the Milwaukee MC122 pH Controller – a trusted tool designed for precision, automation, and peace of mind. Whether you're growing plants hydroponically, maintaining a healthy aquarium, or fine-tuning a water treatment system, the MC122 offers continuous pH monitoring and on/off control, so you can set it and forget it.
Equipped with a high-accuracy pH electrode, adjustable setpoint, and LED alarm system, the MC122 gives you full command over your pH environment. Once connected to a dosing pump or CO₂ system (not included), it becomes an automated solution that helps maintain your ideal pH range – 24/7.
From hydroponic growers to aquarists, lab technicians to industrial operators, the MC122 delivers reliable control in a compact, easy-to-use unit trusted worldwide.
Why Choose the Milwaukee MC122?
- Continuous Monitoring – Real-time pH readings with automatic regulation.
- Precision Control – Set your ideal pH range (setpoint adjustable from 5.5 to 9.5 pH).
- Built-In Alarm LED – Visual alerts when pH is out of range.
- Compact & Easy to Install – Wall-mountable, durable housing.
- Includes Quality pH Electrode – Ready to go right out of the box.
- BNC Connection – Compatible with a wide range of pH probes.
- Ideal for Automation – Control acid/base dosing or CO₂ injection with ease.
Proper Care & Maintenance
To keep your MC122 performing at its best:
- Always store the pH electrode in storage solution (not water).
- Clean the electrode regularly using a cleaning solution (like MA9016).
- Calibrate often using pH buffer solutions (like MA9004 and MA9007).
- Replace the electrode as needed to maintain accurate readings.
We recommend adding the Milwaukee pH Maintenance Kit (PH-Main) to your order to support cleaning, calibration, and storage from day one.
Automate with Confidence. Trust Milwaukee.
Whether you're growing, brewing, farming, or treating water – the Milwaukee MC122 is your reliable partner for pH control. Designed to simplify your workflow and protect your results, it's the perfect balance of performance and peace of mind.
Specifications
Application
pH Controller for Hydroponics & Horticulture
Maintaining the right pH in your nutrient solution is critical to maximizing plant health, nutrient absorption, and overall yield. Even small shifts in pH can lock out key nutrients, leading to deficiencies and stunted growth. That’s where the Milwaukee MC122 pH Controller steps in.
Designed specifically for growers, the MC122 continuously monitors the pH level of your nutrient reservoir and automatically activates a connected dosing pump (not included) when the pH drifts out of your desired range. This means it can add pH-lowering (or raising) solution as needed – without any manual testing or adjustment.
Whether you're growing leafy greens, tomatoes, or herbs, the MC122 helps you maintain a stable root-zone environment. By keeping your pH level consistently within the optimal range, it eliminates one of the most common causes of plant stress in hydroponic systems. That means healthier plants, faster growth, and bigger yields – with less daily effort.
How to Use in Hydroponics:
- Calibrate the controller with standard buffer solutions.
- Place the electrode in your nutrient reservoir.
- Connect a dosing pump or CO₂ system to the controller’s power outlet.
- Set your desired pH setpoint.
- The controller will switch the dosing system on/off to maintain pH stability.
pH Controller for Aquariums & Aquaculture
Stable pH levels are essential for the health and wellbeing of fish, aquatic plants, and corals. Even minor fluctuations can cause stress, disrupt biological balance, and make aquatic life more susceptible to disease. The Milwaukee MC122 pH Controller takes the guesswork out of maintaining ideal pH by providing continuous monitoring and automated control.
Ideal for both freshwater and marine aquariums, as well as larger aquaculture setups, the MC122 can be connected to a CO₂ regulator or pH dosing system (not included) to maintain precise pH levels 24/7. When the pH drifts outside your set range, the controller automatically turns the connected device on or off to bring the water chemistry back in line – no constant manual testing or adjustment needed.
This is especially valuable in planted aquariums where CO₂ injection is used to boost plant growth, or in reef tanks where corals require a narrow pH range to thrive. In breeding tanks or fish farms, the MC122 helps prevent dangerous pH swings that could otherwise impact reproduction or growth rates.
By automating pH stability, the MC122 creates a safer, more predictable environment for aquatic life – making it easier to build and maintain a balanced ecosystem.
How to Use in Aquariums:
- Calibrate the pH electrode.
- Place the electrode in your aquarium or sump.
- Plug your CO₂ solenoid valve or dosing system into the controller.
- Set the target pH range.
- Let the MC122 maintain balance automatically.
pH Controller for Water Treatment & Purification
In water treatment and purification processes, maintaining precise pH levels is critical for both safety and performance. pH affects how well chemical reactions occur – such as neutralization, coagulation, precipitation of metals, disinfection with chlorine, and removal of contaminants. Deviations from the ideal pH range can compromise efficiency, increase chemical usage, and result in non-compliance with environmental regulations.
The Milwaukee MC122 pH Controller offers a straightforward and reliable solution for managing pH in smaller-scale treatment systems or laboratory setups. It continuously monitors the pH level of your water and automatically controls dosing by switching an acid or base delivery system (dosing pump not included) on or off depending on your pre-set pH threshold.
Its compact footprint, dependable performance, and user-friendly design make it a practical tool for ensuring optimal water quality and regulatory compliance – without requiring constant manual oversight.
How to Use the MC122 in Water Treatment & Purification:
- Install the Controller – Mount the MC122 near your water tank or treatment system. Make sure it's protected from splashes and has access to a power outlet.
- Connect a Dosing Pump or System – Connect a compatible dosing pump (sold separately) that delivers either acid (to lower pH) or base (to raise pH), depending on your system’s needs.
- Insert the Electrode – Submerge the included pH electrode into your water system, ideally in a spot with consistent flow for accurate readings.
- Set Your Desired pH Range – Use the dial on the front panel to set the pH level you want to maintain. The controller will turn the dosing system on or off automatically when readings fall outside this threshold.
- Calibrate the Electrode – Before use, calibrate the probe using pH 7.01 and pH 4.01 buffer solutions to ensure accurate readings.
- Monitor and Maintain – Regularly check the probe for buildup and clean as needed. Replace the electrode periodically to maintain optimal accuracy.
By automating pH control, the MC122 not only improves treatment results but also reduces the time, effort, and potential for error that comes with manual testing and dosing.
pH Controller for Laboratories & Educational Use
Maintaining a stable pH is often crucial in laboratory and educational settings – whether you're running a chemical experiment, studying biological processes, or demonstrating pH-dependent reactions in a classroom. The Milwaukee MC122 pH Controller is a smart, affordable solution that brings automation and continuous monitoring into the lab.
Designed for real-time observation and consistent pH regulation, the MC122 fits seamlessly into experimental setups where precise control over solution pH is required. It allows instructors and researchers to focus on the science, rather than worrying about manual adjustments or fluctuations that could compromise data or outcomes.
In educational environments, the MC122 is an excellent tool for demonstrating:
- Acid-base titrations and buffering capacity
- The impact of pH on enzyme activity or microbial growth
- CO₂ control in aquatic environments for biology and ecology studies
- Water chemistry and environmental science applications
In laboratories, the controller supports:
- Pilot experiments involving automated dosing
- Consistent pH in fermentation, chemical synthesis, or electrochemical studies
- Long-term monitoring and reaction stability in controlled systems
The unit’s clear digital readout, adjustable pH set point, and plug-and-play compatibility with standard dosing pumps (not included) make it ideal for both students and researchers. Compact and reliable, the MC122 brings professional-grade control into an accessible and user-friendly format.
How to Use the MC122 in Laboratory & Educational Settings:
- Mount the Controller – Place the MC122 in a secure location close to your experiment or demonstration area. Ensure it’s visible for observation but away from splashes.
- Connect the Electrode – Submerge the pH electrode into your beaker, flask, or reaction vessel. For best results, use it in well-mixed solutions to avoid localized readings.
- Attach a Dosing System (if applicable) – If your experiment requires automated pH control, connect a dosing pump filled with acid or base. For demonstrations, manual dosing can be triggered when the controller alerts you to a pH shift.
- Set the Desired pH Value – Use the adjustable set point dial to define your target pH. The controller will automatically activate the dosing system when the pH drifts outside the set range.
- Calibrate the Electrode – Use standard pH buffer solutions (typically 7.01 and 4.01 or 10.01) to calibrate the probe before use, ensuring accurate and reliable data.
- Observe & Record – The real-time digital display shows current pH values, making it ideal for visual learning or detailed data logging during experiments.
- Clean & Store Properly – After each use, rinse the electrode and store it in proper storage solution to extend its life and maintain performance.
pH Controller for Homebrewing & Fermentation
Fermentation isn’t just an art – it’s a science. pH plays a central role in shaping the flavor, safety, and overall success of your brew or ferment. The Milwaukee MC122 pH Controller brings precision and peace of mind to your process, allowing you to monitor and regulate pH levels with confidence.
Whether you're crafting beer, wine, kombucha, kefir, or fermented vegetables, maintaining a stable pH throughout the process helps control microbial activity, enhances flavor development, and extends shelf life. The MC122 is your silent assistant – automating pH control so you can focus on the craft, not just the numbers.
This compact, user-friendly unit continuously tracks the pH of your fermentation solution and activates a connected dosing pump (acid or alkaline, not included) whenever pH veers outside your set range. It’s ideal for brewers looking to:
- Fine-tune mash pH for optimal enzymatic activity
- Control lactic acid development in sour beers or kombucha
- Prevent spoilage in wild ferments
- Ensure safe acidity levels in vegetable and fruit fermentations
Whether you're a passionate hobbyist or a small-batch producer, the MC122 helps you achieve repeatable, reliable fermentation results.
How to Use the MC122 for Fermentation & Brewing:
- Mount the Controller Securely – Set up the MC122 in your brewing or fermentation space, ideally close to your fermenter, carboy, or mash tun.
- Insert the pH Electrode – Submerge the pH electrode in your mash, wort, or fermentation brine. Stir gently to get an even reading if the solution is not naturally agitated.
- Set the Desired pH – Use the adjustable set point dial to choose your ideal pH value.
- Connect a Dosing Pump (optional) – If you wish to automate corrections, connect a dosing pump filled with an appropriate acid (like phosphoric or citric acid) or base (like calcium carbonate or baking soda solution). When pH drifts, the MC122 triggers the pump to bring it back in range.
- Calibrate the Electrode – Before each batch, calibrate the electrode using certified pH buffer solutions to ensure accuracy.
- Monitor During Key Stages
· Brewing: Track pH during mashing, boiling, and post-boil cooling
· Fermenting: Watch for shifts during active fermentation and aging
- Clean and Store Properly – After use, rinse the electrode thoroughly and store it in the proper solution to maintain accuracy and extend its lifespan.
pH Controller for Pools & Spas
Balanced pool water is essential – not only for swimmer comfort but also for equipment longevity, chemical efficiency, and overall water safety. The Milwaukee MC122 pH Controller takes the guesswork out of pH regulation by providing continuous monitoring and automatic control, ensuring your water stays within the ideal range.
Whether you're managing a small hotel spa, a home hot tub, or a private pool, the MC122 helps maintain water quality without constant manual testing and dosing. By automating pH control, it prevents common issues like:
- Eye and skin irritation caused by high or low pH
- Scaling and corrosion in pipes, heaters, and filters
- Inefficient chlorine performance when pH is off balance
- Cloudy water or unsanitary conditions
This smart, compact controller can be connected to an acid dosing pump (not included) to automatically correct pH when it drifts outside your setpoint. It's an ideal solution for owners who want precision without the hassle, especially in pools that are used frequently or exposed to variable conditions (like rain, sun, or heavy swimmer load).
How to Use the MC122 for Pools & Spas:
- Install the Controller Safely – Mount the MC122 near your pool’s pump/filter system or spa control station, in a dry, shaded area that’s easy to access.
- Submerge the pH Electrode – Place the included pH probe in a continuously circulating part of the system – like near the return jet or inside the filtration loop – ensuring it stays wet and clean.
- Set Your Ideal pH Range – Use the controller dial to set the desired pH level. For most pools and spas, the target range is:
· Pools: 7.2 to 7.6
· Hot tubs/spas: 7.2 to 7.8
- Connect to a Dosing Pump – link the controller to a dosing pump filled with an appropriate acid solution (commonly muriatic acid or sodium bisulfate). When the water’s pH exceeds your set limit, the controller activates the pump to restore balance.
- Calibrate Regularly – Calibrate the probe using pH 7.01 and 4.01 buffer solutions to maintain measurement accuracy, especially during seasonal changes.
- Monitor System Alerts – The LED indicator and relay output provide instant status updates, making it easy to know when adjustments are being made.
- Maintenance Tips
· Rinse the pH probe regularly and store it in proper solution when not in use
· Inspect pump tubing and acid containers to prevent leaks or blockages
· Review readings weekly to ensure everything is running smoothly
Result: A consistently balanced pool or spa that feels better, looks clearer, and stays healthier—with less effort on your part.
pH Controller for Industrial Processes
In industrial settings, precise pH control is often non-negotiable – impacting everything from product consistency and operational safety to environmental compliance and regulatory approval. Whether it's electroplating, chemical manufacturing, wastewater discharge, or cooling tower treatment, the Milwaukee MC122 pH Controller offers a cost-effective, compact, and reliable solution for maintaining control over your process.
Designed for continuous monitoring and automated dosing control, the MC122 ensures your pH stays within a defined setpoint – helping avoid:
- Product defects caused by incorrect acidity/alkalinity
- Equipment wear or corrosion from aggressive chemical conditions
- Fines or shutdowns due to non-compliance with wastewater regulations
- Process variability or batch inconsistency in sensitive production systems
The MC122 is a trusted tool for small to mid-scale applications and pilot plants where a simple and effective pH automation system is needed – without the complexity or cost of industrial-grade PLCs or SCADA systems.
Ideal for:
- Electroplating and metal finishing
- Chemical dosing and neutralization systems
- Industrial cooling and boiler water treatment
- Research and development pilot plants
- Food and beverage production lines
- Textile dyeing and finishing
- Pulp and paper mills
- Agricultural water systems
With the MC122, industries gain a simple, accurate, and durable pH controller that takes the stress out of critical pH regulation – freeing up personnel and ensuring your process remains stable and compliant.
How to Use the MC122 for Industrial Processes:
- Mount the Controller in a Safe Location – Install the unit in a protected environment near your process tanks, dosing system, or control panel. The compact design makes it easy to integrate into existing setups.
- Position the pH Probe in the Process Line or Tank – Submerge the pH electrode in an area with active flow or mixing to ensure accurate readings. For aggressive media, consider using a probe holder or protective sleeve.
- Set Your Desired pH Setpoint – Use the simple dial control to define the pH level you want to maintain (e.g., 4.5 for plating baths, 7.0 for neutralization, etc.).
- Connect to a Dosing Pump or Solenoid Valve – Plug the MC122 into a dosing pump that adds either acid or base, depending on your process. The relay is triggered when the pH deviates from your setpoint, automating corrections.
- Calibrate the System – Calibrate the probe regularly using standard pH 7.01 and 4.01 buffer solutions. Frequent calibration ensures measurement accuracy in demanding environments.
- Perform Routine Maintenance
· Rinse and inspect the probe weekly
· Replace the probe as needed, especially if exposed to harsh chemicals or particulates
· Check pump flow rates and refill chemical reservoirs regularly
- Monitor Operation – Visual indicators on the unit make it easy to verify if the pH is within range or if the dosing system is actively engaged. For more advanced setups, the MC122 can be used in combination with data loggers or timers for additional control layers.
Login