fish+aluminium toxicty as a search term in Google would have told you
there is a problem in low pH.
Try this if you want:-
"Aluminium is acutely toxic to fish in acid waters. The gill is the
principal target organ and death is due to a combination of
ionoregulatory, osmoregulatory and respiratory dysfunction. The toxic
mechanism has hitherto received little direct consideration and is
unknown. In this paper the mechanism of acute aluminium toxicity is
approached from a chemical perspective."
Copper has antifungal props so might be a reasonable alternative (for
the water wheel and fish, that is).
Mate of mines wife came in one day and said next doors dog has gone
missing, this BTW was in Oxford. During the conversation she happened
to say I wonder where it is.
My mate piped up, Liverpool.
What makes you think it's at Liverpool ?
'Cause I threw it in the lorry the other day when it wouldn't stop
barking and dropped it off in Liverpool..........................
Visit the new Model Engineering adverts page at:-
Cut up Oxo cubes work OK.
You scatter a handfull over the fence when the night is dark and
rainy. The dog will dig nearly to China to find the great smelling stuff
down in the ground.
Harmless to the dog, maybe even beneficial to get the execise, but the
owners tend not to want to keep them...
I know guys that swear by a little laxative in a dog treat, placed
where they will be found just prior to shutting down the houshold at
night. A little rough on the dog, but not fatal unless overdone.
Then there are things done with electronics and high frequency sound...
Strictly secondhand knowledge being passed on here, mind. But you asked.