Aqua Medic pH Computer Set

A calcium reactor dosed on a timer keeps running CO2 whether your tank needs it or not, which lets pH swing further than a reef tolerates well. Wiring the reactor's solenoid through the pH Computer Set instead means CO2 only flows while pH is above your set point, and cuts out the moment it drops back down - the reactor is doing the same job, just responding to the tank instead of the clock.

• Microprocessor measurement and control - continuous pH reading, not a periodic timer-based approximation.
• 500 W switched socket - plug a CO2 solenoid, doser or other equipment straight into the unit and let it switch power automatically at your set point.
• Selectable control direction - set the unit to switch equipment on above or below your target pH, depending on what you are controlling.
• One-touch electrode calibration - select the calibration key and the unit calibrates itself against the supplied reference fluids.
• Includes what you need to start - plastic-shaft BNC pH electrode and calibration solutions are in the box.

• pH Computer Set control unit with built-in 500 W switched socket
• Plastic-shaft pH electrode with BNC fitting
• Calibration fluids for initial setup

The CO2 solenoid, calcium reactor, kalkwasser doser or other equipment you are controlling - the computer switches power to your existing gear, it does not replace it. An electrode holder or mounting bracket is not confirmed as included; check with us if that matters for your setup.

Aqua Medic also sells a standalone pH Monitor, which reads and can switch a smaller 5 A load but is built primarily as a monitoring and alarm unit. The pH Computer Set is the step up: a 500 W switched output aimed squarely at running a calcium reactor's CO2 solenoid or a similar higher-draw device directly from the pH reading.

Suitable for: pH-triggered control of a calcium reactor's CO2 solenoid, kalkwasser dosing pumps, or other equipment drawing up to 500 W, on freshwater or marine systems.

Not suitable for: switching equipment that draws more than 500 W through its built-in socket, or as a replacement for a dedicated dosing pump's own safety cut-offs.

This is a mains-powered controller switching a live socket output - have it installed away from splash zones and on a circuit protected by a residual current device (RCD), as with any aquarium electrical equipment. The manufacturer's specification lists the unit as 220 V rated; we have not been able to confirm from Aqua Medic's Australian documentation whether Australian stock ships multi-region rated or needs a step-down transformer for our 230-240 V supply. If that matters for your installation, contact us before ordering and we will confirm with our supplier.

Recalibrate the electrode roughly every four weeks using fresh Aqua Medic pH 7 and pH 9 calibration fluid, and replace the electrode itself when it stops holding a stable calibration - Aqua Medic backs the glass membrane on its pH and mV electrodes for six months as a wear item rather than under the full unit warranty.

• Aqua Medic pH 7 Test Fluid 60ml - for routine two-point calibration.
• Aqua Medic pH 9 Test Fluid 60ml - pairs with the pH 7 fluid for a full calibration.
• Aqua Medic Refillable Plastic pH Probe 120mm - a spare or replacement electrode for when the original wears out.

Sold with the benefit of Australian Consumer Law's consumer guarantees regardless of any separate manufacturer terms. The electrode is a wear item with a shorter service life than the control unit itself - see Care and maintenance above.

Can the pH Computer Set run my calcium reactor's CO2 solenoid directly?

Yes - the unit switches up to 500 W through its built-in socket, which comfortably covers a standard CO2 solenoid valve, and it will cut power once your tank reaches the pH you have set.

Do I need a separate pH monitor as well?

No - the pH Computer Set both measures and displays pH, so it replaces a standalone monitor for the electrode it is connected to.

How is this different from the Aqua Medic pH Monitor?

The pH Monitor is built primarily around reading and alarming, with a smaller 5 A relay; the pH Computer Set is built around control, with a 500 W switched socket sized for equipment like a calcium reactor's CO2 solenoid.

What happens if the electrode fails?

The control unit keeps working - you replace the electrode on its own using a compatible BNC pH probe, such as Aqua Medic's refillable plastic probe, rather than replacing the whole computer.