Nanobubble Carbon Based Airstone with Ultrasonic Stimulus

Looks to be compressed canned oxygen being injected through a carbon-based ceramic/ biochar filter and excited by ultrasound or vibration like an electric toothbrush type apparatus?

I think the ultrasound is in place of the jet stream underwater. You need stimulus to move the micro bubbles off the porous substrate they are being blown through. The water must also have electrolytes or salt in order for the collapsing micro bubble to become and STAY a nano bubble. There is something about the exchange of ions between the collapsing bubble and the electrolytes that keep the nano bubble stable.