Should the inside of my glass diffuser be filled with water? The one I got is this
so basically I have a long J shaped glass tube that connects on one end to my air tubing and the other end coils around inside of an upside down elongated glass bell that has a ceramic disk cap. Should the area between the inside of the bell and the outside of the coil have water?
Seems like it might get better diffusion if the CO2 hits water inside the bell, under the ceramic disk, and then diffuses through the disk out into the aquarium. However, I'm worried the water may somehow make it impossible for air to push through the disk because of added pressure.