Hey Cam- cool. I really dont consider this debate, but instead discussion. I'm glad we can do so on good terms. Now, lets get to the meat of it....There are many species that are brackish, and many that are capable of going between heavier salinities to brackish- this is correct. Yet, I would hardly call these fish we keep in our aquariums. We mostly keep reef fish, due to their size, colors, and tolerance. This is what I'm referring to. These fish do not naturally encounter such salinity swings. Even so, I'm not sure flash salinity changes can be applied to fish tolerance in lagoons, inlets, etc. Do the fish that live in these areas simply stay put when a load of freshwater makes the very "local" environment less saline, or do they evacuate to a saltier area? I would guess the latter.
Regarding the fish kill statement I made- I perhaps didn't make my point clear and spoke out of line. I understand animals will die, or be killed, or need to be euthanized at times. This, I have no issue with. What rubbed me the wrong way was the "guarantee" comment. You are correct, we all have investments in our tanks (many of us- very considerable investments). I anyone decided that an animal had no place in their tank to save their investment, I agree. If someone decided a fish was untreatably doomed, and culled it, I agree. However, to me, it is irresponsible, and unethical in this hobby to cull a fish to simply collect a refund or guarantee. Treating fish as expendable and replaceable for the sake of profit has no place in this hobby (in my own opinion).
Now, to hypo- this is my point. You say it "puts excess work on the kidneys". To me, biologically- this EXACTLY means it has deleterious effects on the excretory system. You are applying a environment to this fish that is causing undue stress and harm to it's body. How much harm? I dont know and I have never claimed to know. Is it reparable? Perhaps, in fact, likely. But, back to my original point- it is negetively effecting them. I hope everyone can see this is the crux of my point. Hyposalinity is being thrown around here as having no negative effect on the fish. This can't be true, because otherwise the fish could sustain lower salinities, or even the same lowered salinity eternally. In reality, I could make the claim that hypo destroys lateral line tissue. I have seen extensive HLLE in fish that are kept in hypo- far greater than in other systems at normal salinity. I am NOT MAKING THAT CLAIM, because I dont have any data to back it up at all. But my theory has just as much validity as everyone elses who says it doesnt hurt the fish. We both have our undocumented and unstudied observations, which show two opposite conclusions.
So getting back to Brandons original question to me- why do I oppose hyposalinity as a prophyalctic treatment? Because it negatively impacts the fish, possibly unecessarily at a time when the fish is already under great stress. Let me ask this question back- if I kep a fish in a QT tank, at normal salinity for 6 weeks, and it never shows the telltale "white spots", flashes, shows respiratory distress, or other symptoms, can it have ick?
