In order to obtain the finest bubbles before connecting the rock or stone to the air distribution (compressor + tubing), before use, it‘s first necessary to immerse the rock or stone for 1-2 minutes in the water.

In time, rock or stone may cease to form fine bubbles. Usually this is caused by algae either on the surface or inside. In this case, you need:

1.) to put the rock or stone on the windowsill inside to dry and then re-connect, the rock or stone will continue with patina, but after connection soft bubbles will form again

or

2.) to immerse the rock or stone in the water solution with Savo and let it dry. This will ensure that the rock or stone will be beautifully clean without algae both inside and on the surface, and will re-form fine bubbles