CO2 Refill Adapter — Paintball to W21.8

Paintball CO2 cylinders are widely available, inexpensive to purchase and refill, and provide a practical alternative CO2 source for small planted aquariums. This compact brass adapter allows a standard paintball cylinder with its proprietary valve to be connected directly to aquarium CO2 regulators with W21.8 inlet threading, without the need for a dedicated aquarium-specific cylinder. This is a cost-effective solution for aquarists who want pressurised CO2 at a low entry cost, or who have paintball equipment already. The adapter is machined from solid brass and rated for CO2 pressures. Note: ensure the paintball cylinder contains only CO2 and not compressed air or nitrogen before use in a planted tank CO2 system.