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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.

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Webinar to explore AMR in vet dentistry

News Story 1
 The WSAVA has invited veterinary professionals to a webinar on responsible antibiotic usage in dentistry.

On 19 November 2025, at 1am, Dr J Scott Weese and Dr Brooke Niemiec will share the latest advice for antimicrobial use. They will present research on oral bacterology, and explain how attendees can choose appropriate antibiotics.

The session will cover pre-, intra- and post-operative guidelines, with recommendations for various pathologies.

The webinar is designed to support veterinary professionals to make informed decisions and tackle antimicrobial resistance.

Attendees can register here

Click here for more...
News Shorts
Bluetongue reaches Wales for first time in 2025

The Animal and Plant Health Agency (APHA) has revealed that bluetongue has been confirmed in Wales for the first time in 2025.

In their latest statistics, APHA records a total of 109 cases of BTV-3 or BTV-8 in Great Britain in the 2025-2026 vector season.

The total number of BTV-3 cases in Great Britain this season is 107. This includes 103 cases within the England restricted zone and four cases in Wales.

There has also been two cases of BTV-8, which were both in Cornwall.

As a result of the cases in Wales, a Temporary Control Zone (TCZ) is enforced in Monmouthshire. Animals can move freely under general license within the England Restricted Zone, however animals with suspected bluetongue must stay on their holding.

All premises testing positive for blue tongue can be viewed on this map.