"John" wrote in message
oups.com...
My pond goldfish are dying. Possible causes?

? The heat

reduces the ability of water to hold oxygen.

? Filling up pond with tap water after evaporation due to heat

Chlorine/Chloramine in the tap water damages fish gills, you need an
additive to neutralise it.

? Clearing out plants clogging the pond

Reduces the oxygen production in the system.

? Disturbing sediment, including submerged rotting leaves.

Releases methane and Carbon Dioxide in the 'swamp'

? Scooping off duckweed with metal sieve

Increases the amount of sunlight to the water depths, increases algae
activity, reduces oxygen availability.

? Cherries falling into pond from nearby tree

The water seems not to have properly settled since the plant thinning,
and to be a bit murky

Increased Dissolved Organic Compounds (DOC) reduces oxygen availability.

So any or all of the above will cause trouble.
Get an air pump and airstone (any size) to increase aeration and surface
movement to improve
oxygen content.
Try not to do all of the above in one go again.

Dave