%efficiency perhaps.
When all the gas is being dissolved into solution is likely what is being stated.
For a 72 gal, about 2 bubble sec is a good starting point. Adjust to the pH/KH table and that's all you need to deal with.
http://www.sfbaaps.com/reference/table_01.shtml
So for your tank at a KH of 4, shoot for a pH of 6.6 for 30ppm.
20-30ppm is good.
Keep adding more CO2 till you get in this range.
Make sure the pH is 6.6-6.8 the ENTIRE lighting period. Never higher than 6.8 when the lights are on.
I tend to error on the higher side since the KH and pH kits can be off a little and generally this range of CO2 is not harmful to fish with healthy growing plants(these produce lots of O2).
Being off by 0.2pH units can drop the CO2 level down 10ppm etc also, similar issue with KH. KH measurements are easier generally and more reliable. I use a good pH monitor with a probe to get a good pH reading and I don't have to test since it's a digital read out etc, just flip a switch.
Erythromycin does indeed work but........it cost X amount of $$ for treatment of a large tank x 5 days.
Blackout cost = 0.00$ and takes three days and there's no shipping/travel related cost.
As far as the name game, if you want to argue it should be called something then talk specifically, genus name is Oscillitoria, non heterocyst forming filamentous colonial. Phycologist have both in the past and the present done the work on this group and few microbiologist study Cyanophyta/bacteria. It's a rather silly name game. Some folks concern themselves with these issues, be my guest. Cyanophyta/bacteria is radically different than other bacteria such as structually(possesses thylakloids), biochemically and specialization, eg heterocyst/chain forming etc. I'd say they are not really bacteria either..........
I study BGA's, and am quite good at FW BGA identification/biochemistry. We have no issue amongst ourselves with this name or others, we use the specific name when we want to be less mundane.
The three genera you might encounter, Oscillitoria(most common, in all tank samples from all over the world), Phormidium, rare in one very filthy tank(common in nature), and Anabeana in Azolla the only heterocyst forming BGA in aquariums(not free living).
Regards,
Tom Barr