Your data on MRCVSonline
The nature of the services provided by Vision Media means that we might obtain certain information about you.
Please read our Data Protection and Privacy Policy for details.

In addition, (with your consent) some parts of our website may store a 'cookie' in your browser for the purposes of
functionality or performance monitoring.
Click here to manage your settings.
If you would like to forward this story on to a friend, simply fill in the form below and click send.

Your friend's email:
Your email:
Your name:
 
 
Send Cancel

Study suggests ion generators could be harmful to fish
Scientists found the ion generators can produce high concentrations of copper and zinc that are harmful to fish.
Researchers conclude generators produce toxic levels of copper and zinc.

Copper ion generators used to control algae growth in freshwater ponds generate high concentrations of metals that could be harmful to fish, according to new research.

The study, published in Vet Record, concludes that ion generators might not be safe for fish and that copper should only be used to prevent algae growth if concentrations are monitored closely.

In the study, researchers carried out physical and postmortem examinations on two koi fish that had died in a pond fitted with a copper ion generator (Aquascape IonGen). They concluded that heavy metal toxicity was the likely cause of morbidity and mortality, which was supported by a heavy metal screening of the owners’ pond.

The team also carried out tests to see whether the IonGen produced toxic levels of copper and zinc. They found that the tank containing the IonGen had higher concentrations of copper and zinc, and copper levels exceeded those associated with toxicity in both hard and soft water.

The researchers conclude: 'Cu ion generators such as the IonGen can produce Cu concentrations that have detrimental effects on the health of koi. Although both Cu and Zn toxicities are dependent on water hardness and other geochemical parameters, the experiment suggests that the IonGen has the capacity to produce Cu at levels that are toxic regardless of water hardness.'

They continue: 'Cu ion generators should not be used in freshwater ponds that contain live plants and animals due to the risk of chronic and unpredictable Cu exposure, and veterinarians should consider Cu ion generators as potential sources for Cu toxicity in freshwater fish, especially in ponds with soft water.'

The study was conducted by researchers at the North Carolina State University College of Veterinary Medicine and the University of Pennsylvania School of Veterinary Medicine.

Become a member or log in to add this story to your CPD history

RCVS announces 1CPD app update

News Story 1
 The RCVS has announced a new version of its 1CPD mobile app, with enhanced features for veterinary surgeons and veterinary nurses to record their continuing professional development.

The mobile app includes a new 'what would you like to do?' shortcut for frequent tasks, a notification badge, and the ability to scan a QR code from the home screen to easily record an activity.

Users will be prompted to update the app from the App Store or Google Play the next time they log in. For more information, visit RCVS.org.uk 

Click here for more...
News Shorts
Nominations open for RCVS and VN Council elections

The nomination period for the 2026 RCVS Council and VN Council elections is now open, with three veterinary surgeon seats and two veterinary nurse seats available.

Prospective candidates can download an information pack and nomination form from the RCVS website. Individuals can nominate themselves for the elections, with the results to be announced in the spring.

Clare Paget, the recently appointed RCVS Registrar and elections returning officer, said: "If you want to play your part in influencing and moulding how the professions are regulated, and making key decisions on matters of great importance to your peers, the public and animal health and welfare, please consider standing for RCVS Council or VN Council next year."

Nominations close at 5pm on Saturday, 31 January 2026.