Danish Blue Unit’s measurement system for salmon farming moves from land to sea for the first time, when it is implemented on live fish carrier vessels from Sølvtrans AS to optimise measurements on board.

In November, the first vessels from Norwegian Sølvtrans AS will launch with the measurement system Blue Unit Lab Station installed. Following a pilot project of three months, where the system has been tested, the Norwegian shipping company is now convinced by its function and ready to install Blue Unit’s system. The live fish carriers transport smolt between land-based and sea-based farms. In addition, the two cargo tanks with a total of 3900 m³ (approximately 857880 UK gallons) are used to de-lice the fish.

– Blue Unit has been tested on one of our vessels after the wish by a client, and we’re very happy with the results, as it can detect hydrogen sulphide (H₂S) at minutes’ notice. Previously, we have had a few incidents, where we had difficulty tracking the dangerous chemicals in time, says Emil Eide Høyesen, Fish Health Specialist at Sølvtrans AS.

Blue Unit Solution is a monitoring system for RAS-farms with specially designed censors collecting thirteen vital water quality parameters from up to twelve locations at a time, which helps improve water quality, reduce costs, and increase animal welfare in the fish farms. This is the first time Blue Unit’s system has been tested at a waterborne location.

Bad readings can be catastrophic

Loading and unloading can stress the fish. This can make them excrete several different substances that can affect the water quality. These include hydrogen sulphide. If H₂S is found in the cargo tanks, the shipping companies' ships are quarantined. It takes a short while from when the hydrogen sulphide can be measured until the fish die.

– Our online system can measure H₂S in 24-hour operations, which means that negative readings can be detected in time. That way, many issues can be fixed before they become catastrophic for the fish farmers. It is crucial in good fish farming that you can trust your measurements, and that they are constantly up to date, says CEO at Blue Unit Solutions, Henrik Hamann Juel.

A voyage from land to water farms takes between ten and twelve hours, so a lot can happen if the water measurements are not constant. Among other things, there is a risk of moving potential toxins from boat to farm if you are not aware. Thereby, the entire stock is affected - both the existing and the new stock. On the other hand, if H₂S is detected immediately, chemicals can be added that will affect the water and bring it from a dangerous to a harmless solution.

The censors exit the cargo tanks

The problem with hanging censors, which is the standard today, is that they are placed within the cargo tank at all times. Therefore, they are difficult to access and clean of algae and dirt that interfere with the measurements. If a water sensor is to work optimally, it must be clean and free of any algae formation, which is almost impossible with hanging sensors.

– The censors from Blue Units lab station are located on deck in boxes above water with hoses connected. This makes the system easy to install, use, read and clean. It is very user-friendly, says Emil Eide Høyesen.

Facts: Blue Unit Solution

• An all-in-one water quality monitoring system with subscription-based software that collects data and gives 24/7 insight into the farm’s status
• Specially designed censors measure the following water quality parameters: pH, O₂, opaqueness, conductivity, redox, rH (redox less pH), salt contents, temperature, totally dissolved matter, available CO₂, total CO₂, H₂S, non-carbonate alkalinity (surrogate of ammoniac)
• 2700 datapoints daily that are uploaded to the Cloud accessible via external units
• Early warning system that shows where, when, and why changes in water quality occurs
• Built-in alarm system triggered by critical levels
• Compares benchmark values with similar farms in the industry.

• Blue Unit is a Danish technology- and consultation company, a world-leader in data mining for industrial RAS-farms.