Hi mate, remember they are only rules of thumb, not hard and fast rules. Generally people go for max fish for their biofilter and this is where these rules are more applicable.
My understanding, and I may be wrong I frequently am, its the fish that cause the ammonia transfer not so much the feed and you are right 5 fish in an IBC doesn’t require the same filtration as 25 fish, of the same size.
I don’t turn the water over every hour but I do have the required biofiltration.
If you want scientific specs then that’s over my head and can’t help, I like a comfort level and don’t push limits so much.
If you had 2000 trout in your pond would turning over the volume every hour seem sensible?
I know of large dams where the biofilter is the dam walls, the surface of the water is the oxygen transfer and they have no problems. Except birds of course.
I’m sure there would be calculations and perhaps some of the brainiacs of the forum can be of more help.
