Spiral Diffuser Setup Instructions
While Spiral diffusers will emit small CO2 bubbles as soon as they are connected to the CO2 source, the spiralling effect will not happen immediately. For this to occur, the diffuser needs to be left submerged in the aquarium to allow water to fill the glass chamber of the diffuser - as indicated with the line in the photo opposite. It may take a few days for this to happen. Alternatively, a syringe could be used to inject water down the input hole to fill the diffuser faster.
Until that happens, you may find the CO2 escapes from a small hole at the bottom of the spiral coil, as indicated with the arrow in the photo opposite. Rest assured, the hole is meant to be there and this is normal behaviour. Once the diffuser has filled with water the CO2 will stop coming through this hole and instead spiral up the coil.