Water type
Freshwater + Marine
Part no.
220.13
Warranty
6 months
Size
≈110 mm overall (70 mm ahead of thread)
Test method
Electronic probe
Kit life
1 to 3 years in use
Aqua Medic pH Probe L70mm - Plastic PG 13.5mm Threaded
The pressure-rated version for probes that live inside a reactor or a length of pipe. This Aqua Medic pH probe (model 220.13) has a plastic PG13.5 threaded body rated to 3 bar, so it seals directly into a fitting on a calcium reactor, nitrate reactor or closed pipe run instead of sitting loose in a sump. Overall length is around 110 mm including the threaded cap, with roughly 70 mm ahead of the thread; it terminates in a BNC connector for Aqua Medic monitors and controllers.
Key features
- PG13.5 threaded body – screws into a matching PG13.5 fitting for a sealed, in-line installation.
- Rated to 3 bar – holds pressure inside closed reactors and pressurised pipe runs, where an open probe can't be used.
- BNC connector – plugs straight into Aqua Medic pH monitors and controllers, and most third-party BNC-input instruments.
- Compact body – around 70 mm ahead of the thread, suited to tight reactor fittings where a longer open probe won't fit.
Specifications
| Spec | Detail |
|---|---|
| Manufacturer part number | 220.13 |
| Thread | PG13.5, plastic |
| Length ahead of thread | Approx. 70 mm |
| Overall length incl. cap | Approx. 110 mm |
| Pressure rating | Up to 3 bar |
| Connector | BNC |
| Compatibility | Aqua Medic pH monitors and controllers; most third-party instruments with a BNC pH input; fittings using a PG13.5 thread |
Suitable for, and not suitable for
- Suitable for in-line installation in pipework, calcium reactors and closed nitrate reactors, on freshwater and marine systems, where the fitting takes a PG13.5 thread.
- Not suitable for open placement in a sump if you don't have a PG13.5 fitting to seal into – use the L127mm plastic standard probe for that instead.
Care and maintenance
Immerse only the tip – a few centimetres – into the measuring medium; the electrode is a wear item and not designed to be fully submerged past that point. Recalibrate regularly against Aqua Medic pH 7 and pH 9 test fluid, and keep the tip wet between uses. Clean with Aqua Medic pH/mV probe cleaning solution if readings drift between calibrations.
Goes well with
- Aqua Medic pH/mV Probe Cleaning Solution 60ml – for removing deposits that cause drift.
- Aqua Medic pH 7 and pH 9 test fluid – for calibration.
- Aqua Medic pH Probe L127mm Plastic Standard – the open-body version, for sump or measuring-cup placement.
Warranty and delivery
Covered by Aqua Medic's six-month electrode warranty, in addition to your rights under Australian Consumer Law – shorter than other Aqua Medic equipment because pH and mV electrodes are a genuine wear item. Standard parcel delivery.
Common questions
What does "PG13.5" mean, and how do I know if my reactor takes it?
PG13.5 is the thread size and pitch of the fitting. It's the standard size Aqua Medic uses on its own reactors and pH fittings; check your reactor's probe port against a PG13.5 fitting before ordering if it isn't an Aqua Medic unit.
Can I run this at full aquarium pressure through a canister filter line?
It's rated to 3 bar, which covers typical reactor and pipe-run pressures. If your system runs higher than that at the probe location, check with the reactor manufacturer before fitting.
Is this the same probe as the L127mm standard version, just shorter?
No – it's a different design. The thread and 3 bar pressure rating are what let it seal into a closed fitting; the standard probe has no thread and isn't pressure-rated.
How far in should the probe sit?
Aqua Medic recommends immersing only the tip, a few centimetres, into the measuring medium.




