Plant Doctor Archive

Water Gardens — Fish dying

I bought some new fish recently but they all died within two days of putting them in my pond. All my other fish are ok, though.

This is reasonably common and I wouldn't be too quick to blame the shop you bought them from. Have you checked the water quality of your pond lately? Ammonia and/or nitrite, pH and phosphate levels should all be checked. pH especially has a nasty habit of slipping in an established pond and the fish will gradually adjust.

New fish, however, do not have several weeks or months to adjust and are shocked by the sudden exposure to vastly different conditions from those they are used to. They may die directly from the shock, but usually what happens is their immune system is suppressed and they fall prey to any infections that are going around. A few test kits are a good investment.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.