F
fishdance
, you are frequently making suggestions regarding the latest and greatest aquarium-building materials and techniques, or cutting-edge new filtrations methods, which are always interesting but only in an academic sense to the vast majority of aquarists. A shade-tree mechanic with a couple of cars he likes to work on doesn't really have a reasonable way to utilize the methods that are used in a gigantic General Motors car assembly plant. A hobby shooter producing his own ammunition, one round at a time, on a bench in the basement, doesn't care how a huge Remington plant does it because he simply can't operate that way.
You also discuss all sorts of esoteric studies of the minutiae of water chemistry and biofiltration...again, interesting but unimportant to most of us...suggesting that the common knowledge of the aquarium hobby is out of date...but have no problem using aquarists from a century ago as an example of why water should be saved! As Rick Sanchez might say: pick a lane!
I don't believe anybody has suggested that aquarium water is sterile...but rather that the water itself doesn't have enough bacteria in it to worry about losing those few to water changes. Like the vast majority of aquarists, I don't need to worry about saving every single individual bacterium. Sure, an aquaculture facility...or a set-up as large as yours...would benefit from efficient water usage. The extent to which that goal is worthwhile to pursue will vary from person to person, depending not only upon the cost of water in their particular locale but also the amount which they need.
What you are saying regarding so many facets of the hobby is simply meaningless to most aquarists in a practical sense. For some it's even completely false; I'm on a well, so the only cost for the water I use is that incurred in the initial drilling of the well if it isn't already in place (one time expense amortized over at least my lifetime), in equipment (pumps, etc.) to get the water out of the ground and into my house, more equipment to get it back out of my house and back into the ground, and of course the energy expended to do all this and to heat the water. I have to do all that stuff anyways for simple domestic use. The greatest limitation on my aquarium hobby is the cost of electricity to heat the water; in terms of water quality, I would probably be operating at peak efficiency by not using filters and just having a flow-through system.
But that's just me. Obviously, others in the wide wide world have completely different concerns regarding the cost of water. Since most of those people simply are not going to install the kind of NASA-level systems you frequently and casually espouse...they are just going to have to bite the bullet and decide if the cost is worthwhile to them. Will the cost of maintaining X gallons of water be offset by the enjoyment derived from those many gallons in an aquarium?
With all due respect, I believe you need to gear your presentation of information to the audience in question; when a casual hobbyist mentions a water quality problem in his single 100-gallon display tank, telling him that all he needs to do is buy some sheets of laminated tripolyethylnitrocellulose, a $1000 dollar laser welder and some titanium and construct a 10000gallon high-tech filtration device the size of a bus...is interesting but not really helpful to him. The typical aquarist with one tank...or a dozen...will listen to some of the suggestions you have made in the past...and then look around his tiny apartment or house...and just scratch his head and laugh out loud. It sounds like a good idea for a single-panel Far Side cartoon.