I'm sure there are 100 more ways than we know to raise DO levels more effecientely, with no actual pumps..
How about using electrolysis, with a remote hho (browns gas) fuel cell, that also refines and seperates out just the oxygen molecules? Then pumps it into a venturi, on demand?
Seems like it would be absorbed back into the water quicker. Maybe the leftover pure hydrogen could be burned like LP produce c02 at the same time.. i'm not a chemist but it sounds cool
Bottled oxygen (scuba/welding/medical grade) could technically be considered more dangerous than a small hydrogen cell but should work just as well? I've seen vids of guys injecting it in, straight from bottles, and those expensive breathing machines. I actually had one of those but it came out of a nasty moldy junk RV, so I didn't plug it in lol..
I guess if we unlocked some secret like how to reverse engineer a fish lung and breathe underwater just by moving an artificial muscle (or an actuator) we would be using that technology to make other new products too.