Colombo CO2 Adaptor Ring: Connecting 95g to Larger Cylinders

By Pro Shrimp | Published: 2026-11-04

Category: ハウツーガイド

Learn how to use the Colombo CO2 Adaptor Ring to connect a 95g regulator to 800g or 1200g CO2 cylinders safely and effectively.

Quick answer

Use the Colombo CO2 Adaptor Ring to convert a standard 95g CO2 regulator fitting to accept Colombo 800g or 1200g cylinders. Install the ring between the regulator and the larger cylinder, then leak-test the connection before pressurizing.

Why the adaptor ring is needed

Standard 95g CO2 systems such as Tropica Nano CO2, Colombo Advance CO2, and Fluval 95g use a specific thread size that does not match the larger Colombo 800g and 1200g cylinders. The adaptor ring bridges this thread mismatch, letting you keep your existing regulator and solenoid while scaling up CO2 capacity. Without it, the regulator will not seal onto the larger cylinder.

When to use (and when not to)

This adaptor is only for connecting 95g regulators to Colombo 800g or 1200g cylinders. It is not a universal adapter and will not fit other brands or cylinder sizes. If you already own a regulator designed for larger cylinders, you do not need this ring. Also, check that your regulator’s working pressure is compatible with the larger cylinder—most 95g regulators are, but confirm with the manufacturer if unsure.

Safety and maintenance notes

CO2 systems operate under high pressure, so always work in a well-ventilated area and never force connections. Inspect the adaptor ring’s O-rings before each use; replace them if cracked or flattened. After installation, monitor the connection for the first few days for any signs of leaks, such as hissing or a drop in cylinder pressure. Use a commercial leak-detector spray or soapy water—never a flame.

Step-by-step installation guide

Turn off CO2 and depressurize: Close the cylinder valve completely and open the regulator’s adjustment knob to release any remaining pressure. Wait until the low-pressure gauge reads zero. Never remove a regulator while the system is pressurized.
Remove the regulator from the 95g cylinder: Unscrew the regulator from the small cylinder. Inspect the regulator’s threaded inlet and O-ring for wear or debris; clean if necessary. A damaged O-ring will leak even with the adaptor installed.
Install the adaptor ring onto the regulator: Thread the Colombo CO2 Adaptor Ring onto the regulator’s inlet by hand until snug. Do not use tools to tighten—over-tightening can damage the threads or O-ring. Hand-tight is sufficient; the O-ring makes the seal.
Attach the regulator and adaptor to the larger cylinder: Screw the combined regulator and adaptor onto the 800g or 1200g cylinder. Tighten by hand only, then give a gentle final snug. Do not force. If it doesn’t thread easily, stop—the threads may be misaligned.
Leak-test the connection: Pressurize the system by slowly opening the cylinder valve. Apply soapy water or leak-detector spray to the adaptor ring and regulator threads. Watch for bubbles; if bubbles appear, depressurize and reseat the connection. A leak will waste CO2 and may be dangerous—always test before use.
Set working pressure and check for stability: Adjust the regulator to your desired working pressure (typically 1–2 bar for aquarium CO2). Observe the pressure for 10 minutes to ensure it holds steady. A slowly dropping pressure indicates a leak that needs fixing.

Product facts

Colombo CO2 Adaptor Ring 95g to 800g/1200g: This adaptor enables you to use the Colombo CO2 800g and 1200g bottles on standard 95g CO2 systems like Tropica Nano CO2, Colombo Advance CO2 or Fluval 95g systems. It lets you keep your existing 95g regulator and simply switch to larger, longer-lasting cylinders.
Colombo CO2 Adaptor Ring 95g to 800g/1200g