Thanks for the opinions guys! Since I already have the O2 tank and setup, I don't see myself ditching it to get an aquarium pump setup. My O2 tank is a decent size welding tank. I've filled it once and the regulator still shows it's full after lots of brew days. I'm not worried about the expense of the O2! According to the book, with an aquarium pump you can only hope to get at best 8ppm DO, which is the minimum of the recommended 8–10ppm, even with extended aeration (which can be detrimental to head formation and retention, according to White).
Probably good enough to make a good beer though!
Robert, you say it's easy to over-oxygenate with pure O2 – that's the reason behind this formula idea – to dial it in based on the particulars of the wort. But, according to the book, 60 seconds at 1 lpm for 5.3 gal of 1.077 is going to result in the optimal ~ 9.2 ppm DO. If I were to run it for a minute on that wort, and some of the O2 were to bubble out, then I'd assume I'm under 9.2 ppm.
I can dial the flow back to .12 lpm and increase the time x8, or set it to .2 and increase the time x4 – I can get it to flow so that it's not bubbling out of solution. That's what got me wondering about how long to run it, depending on the flow rate, and the characteristics of the wort. I primarily do ales and oxygenate at pitching temps, so temperature is typically ~65–70 when adding O2.
I realize this might be overkill, but for the sake of getting in the ballpark and not over or under oxygenating the wort, I'd love for someone to be able say whether this formula has legs or not.