My friends bought a house that has an approx. 500 gal brick pond with
a waterfall, and some sort of closed external filter. After they
cleaned the filter the fish in the pond started dieing. Some small,
some large, they have five fish left and and some are very young and
others are older. The deaths occurred among established and newly
introduced fish randomly, but did not kill all the fish.
These friends now are questioning me about their problem thinking I
have some expertise because I have had a pond much longer than them.
Yet my ponds either have no filter or a skippy filter. The only fish
deaths I have had were caused by forgetting the hose and chlorinating
the poor things to death, or sucking them up into the pump. I would
think that if cleaning the filter, improperly, released enough ammonia
to kill fish all the fish would die? Maybe this is not the case?
someone else suggested temp. because we are in the deep south and it
has been very sticky lately. Their pond does not get sun all day and
they have goldfish, what would a max temp. be for a pond?
Can someone give me a rundown of the correct way to identify their
problem. I assume testing the water would be the first course of
action.