Hey Brandon, please do not take the follow as an attack, because it is not- I am only trying to show my viewpoint.
Does hyposalinity negatively effect an organism that lives in a comparatively hypersaline environment? You better believe it does. The whole premise of hyposalinity is that the change in osmotic properties is deleterious to a greater extent in a smaller organism than to a larger. We walk that line with our hyposaline treatment. But it still is deleterious to the larger. To whatever degree. Otherwise, we'd have clownfish in freshwater tanks. So, to what degree does the hyposalinity harm a fish? I really have no idea. But honestly, nobody has any idea. Does it stress them physically, mentally, or otherwise? I would argue, yes. Does is damage potentially microflora and microfauna that are internal in fish? Possibly. Does it damage the cpillary cells used for respiration, lateral line detection, or other? Who knows. BUT, does it have the potential to do so? ABsolutely! So, why put a outwardly healthy appearing fish under such stress? Because is may or may not have a parasite? To me, that is unecessary and trivial. Freshwater dips are also a tightrope walk, that we do (with quite a bit of educated predictive success). But does it have deleterious effects on fish? I firmly believe so.
Now, that being said, I think these treatments have their place. Hyposlaine treatments are far easier on the fish systems than other chemicals, in my opinion. So, should one prove to be effective to treat pathogen X, I would do it. But, my point is that even this relatively mild treatment does have some degree of negative impact on a fish, and such negative impact is something I wont apply to my animals unless the diagnosis merits it.
Let me ask, why do you oppose copper as preventative treatment, but not hypo? Copper done properly can be just as safe as hypo done properly (with certain specific species), so where do we draw the line?
Funny that you should bring up major aquariums. Before I put my whole leg in my mouth, let me pre-curse my statement with this- I work at a animal insitution, and I know what is involved in maintaining large, mixed species exhibits. I, <u>in no way,</u></em> am criticizing the techniques of such organiziations. Now, I challenge anyone here to go to any major aquarium and see if they can spot a totally healthy population of fish. It cant be done. Invariably, you will see a fish here or there that has HLLE, or nutritional deficiencies, or parasites, or whatever. This is because the exhibit as a whole cannot specialize to each and every individual fish within. This is the "curse" public aquariums live under. How do they deal with it? They prioritize and "triage" their needs. Freshwater dips and hyposalinity as preventative outweighs the potential stresses of such fish, because they serve the better purpose on the long run. But this I cannot stress enough- <u>WE CANNOT TREAT OUR TANKS LIKE AQUARIUMS TREAT THEIR TANKS!!!</u></em> They are totally different breeds. With different animals, and differnt tools, and different problems. When the lion at the zoo gets sick, they treat it a certain way. Do you think the same techniques, drugs, methods apply to your housecat? They don't.
Again, please dont take my comments as attack, they are not. I agree and approve of the techniques you have outlined. I simply think we must use them in appropriate measures, not as "fix-alls".