More than ten years of experience has resulted in a delousing solution that is highly in demand worldwide.

Our focus has always been the fish and the welfare of the fish. There is no doubt that a healthy and happy fish influence the quality of the end-product. Providing adequate facilities for the fish is therefore not just an investment in fish welfare, but also an investment that will benefit your business.

The FLS Siphon method.

The FLS Delouser is a mechanical delouser that flushes with seawater at seawater temperatures. The delouser is designed as a siphon that collects the fish from the cage and delivers it back to the cage at the same level. The crucial benefit is the lifting heights - see the illustration below;

We know that high pump pressure affects the fish negatively. Therefore, our goal is to carry out the operation with the lowest possible pump pressure. We use a gentle ejector to transfer the water and the fish through the system. With zero lifting height, a pump pressure of only 0.35 - 0.45 bar is necessary to get the perfect water speed of 2 - 2.5 meters per second.

The fish is flushed twice through our carefully developed full water flushers. We set high-quality standards for our products. The flusher must be effective in delousing and, at the same time, handle the fragile fish without inflicting wounds and injuries.

We have achieved to develop a solution that meets our standards due to a combination of the flushers' diameter (and pipelines) and the carefully designed flushing nozzles. The system flushes with a pressure of only 0.55 - 0.85 bar and removes more than 95% of the seal.

Well documented fishwelfare

At FLS, we are concerned with documenting our figures. Therefore, we have engaged veterinary institutes and others on several occasions to assess and document the fish welfare and operation efficiency. We are happy to provide this documentation on request.

A successful delousing is characterized by high capacity (in tons/hour), efficiency (in de-lice%), and good fish welfare (in stress, injuries, wounds, and mortality). It is not difficult to get rid of seals, but it is challenging to achieve this perfect combination.

In our latest delivery at MV Smøla Viking, the FLS Delouser is equipped with four lines and has a capacity of 200 tonnes per hour. We can document mortality down to 0.1% and often more than 95% delousing effect.

Photo: Henrik Johan Svendsen

FLS – a sustainable solution

At FLS, we take a lot of pride in improving fish welfare. Not just because we care about the fish, but also because it is profitable for the farmers.

FLS Delousing is a sustainable method - it treats the fish carefully with low energy consumption. Low pump pressure is also low energy consumption. There are no chemicals involved and no hot water, leading to injuries on the fish.

For more information, please contact CEO Lars Georg Backer (