One word...
pressure
You need 2 bar pressure in your regulator for this to work as it should. Otherwise, there's simply not enough pressure to push the CO2 out of the tightly compacted atomiser plate. Check out the YouTube clip on our website - that's at least 2 bar pressure being run and look how fine the CO2 mist is.
Few other points to consider:
- Some regs won't allow you 2 bar pressure, so another thing to bare in mind (most do though).
- You need to ensure decent connections on your CO2 tubing because the 2 bar pressure can pop off (try the Easy Aqua Double Check Valve as this has screw fittings).
- Sometimes it takes a few minutes for the CO2 to pass from the regulator to the atomiser - don't expect immediate results (like from glass diffusers). This is because pressure needs to build up along the CO2 tubing and then pass into the atomiser.
Lastly, use proper CO2 tubing! Air line tubing is not suitable and will definitely pop off.
Are you using the atomiser? If so tell me what you think. Maybe you haven't decided which diffuser to choose yet so any questions, please ask :)