I do not have DO meter so I do not know what my O2 levels are.
I aerate with similar method in the transfer to the fermentor.
I have about 4 ft 3/8 clear tubing with pinhole on the BK end.
Pinhole allows air to be sucked to the tubing that mixes with passing by wort in the transfer.
On fermenter end I have a wort Sprayer like this:
I have fermented 1066 beers with no problem.
What I mean with "no problem" is 2 week fermentation and about 1014-1016 FG.