Pond Goldfish Problem

by Mags
(UK)

Only recently discovered baby goldfish in pond this past week have found 1/2 dead each day.

Managed to rescue 1 which was initially thought to be dead but after a few minutes it started to swim on its side then 5 minutes later it died.

They were observed eating the pellets so have not died from starvation any ideas about of the problem would be appreciated as we have probably only 2/3 left.

The pond has a filter and the water is reasonably clear and there are lilies and other aquatic plants.

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Grant's Reply

Hi Mags

Remove what fry are left and move them to another container as they are going to need treatment of some sort.

You haven't given me much information so I will assume the fry are under 2 inches (52mm) in body length.

The UK is just into autumn so unless you are up north I assume the water temperatures are still reasonable.

There are a couple of possibilities:

1. A bacterial/fungal attack
2. A parasite attack.

I believe it's parasites because you have a filter installed.
Make sure the filter isn't clogged which would increase the bacterial count in the water.

Assuming the problem is parasites, and you can't see lice or anchor worms attached to the fish there are two other possibilities, protozoan parasites or flukes.

To cover all possibilities add un-iodised salt to their water at 0.3% concentration. (3 grams of salt per litre or a tablespoon per gallon).

Add this gradually over two days if the fish are weak, (which they seem to be). If they start turning on their sides the salt is too strong so remove them from the solution and when they have recovered halve the salt quantity.

The salt will take care of any bacterial or fungal diseases. It will also kill off any protozoan parasites when at 0.3% concentration.

To kill the flukes, a praziquantal based medication is required. (It will also kill off the protozoan parasites).

You will need to start treatment quickly as you can see from the speed of the die off these parasites are very virulent.