You made a few points about my last outburst ... so lets expand.
<snip>
I have always thought that my fish behaved after water changes in a way that
indicated that they enjoyed them and that to means the opposite of stress
<end snip>
Lyn's (huge) Oscars do return to normal quickly, but do not want to be in
the tank during the water change. Perhaps it is because I move rocks they
cannot. Perhaps they do not like the sump turned off, but how else do I
maintain sufficient water to keep it running & know that I have taken "old"
water out (let alone balance what comes in to what goes out)? Anyway, with
the sump off the in tank water currents are very different. The ell tails
positively like me disturbing the environment because it stirs up things for
them.
<next sentence>
At this stage we are brain storming. Hopefully there will be a reader who is
in a position to get funding and start to close these gaps. In the meantime,
throw suggestions in. There are signs and symptoms. For example, there is a
fish in one of my tanks that tells me water conditions have changed before
any of the chemical tests will detect them, his eyes change colour. Learn to
recognise signs, soon you will discover the symptoms.
<snip> Loaches <end snip>
Stupid fish that can hide for long periods, they move very rapidly. My first
loach was bought to control snails that I acquired on a plant added to a
pleasant community aquarium with small fish but many plants. Loaches nose
around substrate, plants, everywhere. Since then many people have commented
to me about loaches ability to control worms; and keep a fish population
healthy. Sorry mate, it is all anecdotal, but there is a lot and most
unsolicited. On this issue I asked questions in an attempt to draw
information.
Simple experiments to give substance, or refute would be easy to arrange.
But I do not appear to have TB in any tanks.
UPDATE
I wrote all that the other night. I have done a couple of water changes
since then Bruce & confirm that the larger fish do react. Small fish appear
to ignore what is happening. As I originally said, the Oscars try to hide.
My larger natives scurry about with the salmon tails frequently hitting the
sides of the tank (they seldom do during the day) and all the fish try to be
somewhere else.
Watching this I am reminded that each morning there is sudden activity in
the big natives tank when the lights go on. There is a double fluorescent
unit with two tubes having different spectrum ranges. One fires up much
faster than the other. The first tube makes most of the fish jump (= stress
point?)
Monty