So after I found out I needed plastids and Oxium for Octavia, I found this way of getting a good amount of Oxium within a few minutes.
(you can get more Oxium if you go for longer)
So first off you head to sharpless on Phobos. It’s a mobile defense mission.
So now you need to defend all the points in order to trigger the Oxium Osprey to start spawing.
So at this point is when you can start farming them, every time you kill them they (from my experience) drop 6-12 Oxium. So this is where you can stay in the level as long as you want the longer you stay the more Oxium you can get. (They longer you stay the more Oxium Osprey spawn)
This was for staying for 4 minutes after the main objectives were completed.
This was only after staying for 7 minutes after completing the main objectives.
So the average I had here was 70-130 Oxium per 3 minutes.
And as a added bonus while you’re waiting for the Oxium Osprey to spawn you can run around looking for plastids.
Original Link – Continuation of discussion