Aqua Medic CO2 Bubble Counter w/- Check Valve
Fits
Aqua Medic CO2 systems (4/6mm tubing)
Aqua Medic CO2 Bubble Counter w/- Check Valve
An inline bubble counter with a built-in check valve, so you can see your CO2 rate and protect your regulator in one fitting. The Aqua Medic CO2 Bubble Counter sits in your CO2 line between the regulator and the reactor or diffuser, giving a clear view of bubble rate so you can dial in dosing by eye. The integrated check valve stops tank water from siphoning back up the line into your regulator if pressure in the system drops.
Key features
- Visible bubble rate — count bubbles per second or minute to set and check your CO2 dosing without guesswork.
- Integrated check valve — a genuine safety feature, not just a counter. It stops water siphoning back into the regulator, which can otherwise corrode the regulator internals or flood the line.
- Simple inline fitting — installs directly into the CO2 line between the regulator and the reactor or diffuser, no tools beyond the standard hose connection.
- Matches Aqua Medic's CO2 system — built to the 4/6 mm tubing used throughout Aqua Medic's CO2 range, including their regulators, hose and reactors.
Specifications
| Function | CO2 bubble counter with integrated check valve |
|---|---|
| Installation | Inline, between regulator and reactor/diffuser |
| Tubing | Aqua Medic 4/6 mm CO2 tubing |
| Check valve | Built in — prevents backflow toward the regulator |
Suitable for, and not suitable for
Suitable for: planted freshwater tanks and any CO2-dosed system running Aqua Medic's regulator, hose and reactor line, where you want a visual check on dosing rate plus backflow protection in one part.
Not suitable for: replacing a dedicated CO2 solenoid or regulator — it's a monitoring and safety accessory, not a control device, and it doesn't regulate pressure or flow on its own.
Safety
The check valve is there to protect your regulator, not just your CO2 line. If system pressure drops — a nearly empty cylinder, a knocked hose, a closed valve — tank water can siphon backward through unprotected tubing and reach the regulator, where it causes corrosion that isn't always obvious until the regulator fails. Running a check valve inline, as this bubble counter does, is standard practice on any pressurised CO2 setup.
Care and maintenance
- Check the counter periodically for any water intrusion on the reactor side of the check valve — a small amount is normal, a rising level over time is not.
- Keep the hose connections firm; a loose fitting defeats the point of having a check valve at all.
Goes well with
- Aqua Medic Regular CO2 Regulator — the regulator this bubble counter is built to pair with.
- Aqua Medic Silicone CO2 Hose 4/6mm — matching tubing for the full run.
- Aqua Medic CO2 Reactor Compact Diffuser — where the CO2 dissolves into the water after the bubble counter.
- Aqua Medic Non Return Valve 4/6mm — extra backflow protection for longer or more complex CO2 runs.
Warranty and delivery
Covered by Aqua Medic's standard manufacturer warranty against defects, in addition to your rights under Australian Consumer Law. Ships as a standard parcel.
Common questions
Do I still need a separate check valve if I'm using this bubble counter?
The check valve built into this bubble counter covers that section of the line. On longer runs, or as extra insurance closer to the regulator, many keepers add a second check valve — it's cheap protection for an expensive regulator.
Where does it go in my CO2 line?
Inline between the regulator (or solenoid, if fitted) and the reactor or diffuser, oriented so you can see the bubbles and in the direction the check valve is designed to block backflow.
What size tubing does it use?
It's built for Aqua Medic's 4/6 mm CO2 tubing, the same size used across their regulators, hose and reactors.
Does it work with non-Aqua Medic CO2 systems?
It's sized for 4/6 mm tubing, which is common across the hobby, but check your existing fittings before mixing brands on one CO2 line.
