Is too much CO2 lost when the diffuser is at the water surface?
You don't have to worry. The gas exchange at the water surface with our breathing air, which also contains CO2, is very important for the aquarium environment. The diffuser should therefore move the water surface and thus promote gas exchange and prevent a build-up of surface scum. Most of the CO2 is already dissolved in the water column coming from the external filter. The membrane of the JBL PROFLORA Direct atomises the CO2 into fine bubbles which are carried along with the flow and dissolve in the hose. Unlike reactors, the bubbles here are very fine and light. The part that is not yet dissolved then swirls around in the aquarium as it drifts in and continues to dissolve. It is normal and unavoidable that some of the bubbles "pop out" at the surface. Nevertheless, this method is very effective.