Critical Spares for Fish Pumps

Lost productivity and downtime due to a minor breakdown of your fish transfer pump, often results in delays and potentialy large costs with wellboats or transport trucks waiting. The remoteness of many farms and hatcheries, is why holding critical spares, on site, for your fish pump is an essential part of your maintenance programme.

Critical Spares Kit for Fish Pumps

    By holding critical spares close at hand, you are reducing the need for costly call outs and efficiently managing the time taken to get your Aqualife pump up and running.

Contact our service centre for a free quotation.

Tel. 01463 250275 Email:

HyroTech Alfa Flex Filter Panels

New Alfa Flex Panel

Sterner is proud to release the new patented Hydrotech filter panel named Alfa Flex. The Alfa Flex filter panel is a breakthrough in designing of filter panels and can increase the capacity of existing drum filters up to 20%. The Alfa Flex filter panel is compatible with almost all drum filters, which are able to fit existing Hydrotech type drum filter panels.

Filtration Speed

Sludge Production (Volume)

Sludge Concentration (NTU)

Mounting instructions (standard assembly execution)

  • One panel per segment will be mounted in the “lifting” direction (+ symbol in the rotational direction). All other panels will be mounted with the symbol – (non lifting) in the rotational direction.
  • The lifting panels will be mounted in a straight row (same position on the drum) throughout the length of the drum, see picture below.
  • If the ALFA-Flex filter panels should be mounted in any other way or if the old filter panel should be used, it should be clearly indicated in the production order.

YSI ProSolo Optical DO Meters

All New YSI ProSolo

The ProSolo digital handheld meter is designed for use with YSI's latest Optical Dissolved Oxygen and Temperature probes.

Combining an extremely durable, user-friendly display with the most advanced DO technology, ProSolo stands alone as the industry's best dissolved oxygen meter at an exceptionally affordable price.


Improvements over the ProODO include, rechargeable battery's, colour display, ODO cap replacement reminder and support with KorDSS software.
The lithium-Ion battery supports a full day of sampling meaning no more battery changes in the field.
Waterproof case and military spec connector makes the ProSolo a rugged and durable device.

Available Sensors

ODO/T Sensor - Like the original ProODO the ProSolo with ODO/T senor measures dissolved oxygen and temperature. It can display oxygen readings in % saturation, mg/L and ppm. It has a longer lasting ODO cap and improved accuracy in high DO. 2 years warranty is also given on the probe, cable and ODO sensor cap.

ODO/CT Sensor - This sensor is the same as the ODO/T but adds a salinity measurement. This means real-time salinity compensation of DO measurements.


New Optical DO/Temperature Cable
ProSolo Handheld
ProDSS Handheld
Not compatible with legacy ProODO Handheld
Longer-Lasting ODO Cap
Improved Accuracy in High DO
Cable Lengths:
1, 4, 10, 20, 30, 50 & 100 m

4 m kit
4 m ODO/CT Cable, ProSolo handheld, soft-sided carrying case
Direct replacement for ODO Field Kit-4, item no. 603192
10 m kit
10 m ODO/T cable, ProSolo handheld, soft-sided carrying case
Direct replacement for ODO Field Kit-10, item no. 603193


Same cable previously offered with ProDSS kits
ProSolo Handheld
ProDSS Handheld
Cable Lengths:
1, 4, 10, 20, 30, 50 & 100 m

4 m kit
4 m ODO/CT Cable, ProSol handheld, soft-sided carrying case
Replaces ProDSS No GPS ODO/CT-4, item no. 627105
10 m kit
10 m ODO/T cable, ProSolo handheld, soft-sided carrying case
Replaces ProDSS No GPS ODO/CT-4, item no. 627106

You can find our more from our range of multi-parameter meters here

Smolt plant invests in sludge drying

Ranfjord Fiskeprodukter will invest about 20 million NOK in sludge treatment at its smolt plant in Mo i Rana. The environmental investment is made to meet public requirements. It is the sludge from the filtering of the effluent which will be dewatered and dried.

The process solution consists of thickening, dewatering and evaporation. In practice, zero effluent will be obtained from the sludge treatment itself. This is accomplished by purifying the rejection water from the sludge thickening by ultrafiltration.

“Using this sludge treatment, we achieve an overall lowering of our effluents, thus fulfilling public requirements,” says Bjørn Myklebust, managing director at Ranfjord Fiskeprodukter.

At the same time as the investment meets environmental concerns, the sludge will be dried to 90% dry matter.
“It is important for us to get a dried and stable end product. At the same time we use a drying process that is gentle on the nutrients in the sludge, so that it can become the most useful fertilizer product. The aim is to contribute to a circular solution, where waste from fish farming will play a part in agriculture,” says Myklebust.

The drying process utilizes heat pump technology. The process includes several stages where a special Norwegian-developed onion thickener gives a very effective thickening.

The complete sludge treatment plant will be delivered by Sterner and the design basis for the plant is 600 tonnes of fish feed per year.
“We chose the solution after seeing similar plants in operation,” says Myklebust.

The actual sludge treatment accounts for half of the total environmental investments. Sterner has so far delivered 12 sludge treatment plants to the aquaculture industry and besides also works with the production of biogas from corresponding sludge.

Ranfjord Fiskeprodukter AS is located at Mo Industripark, about 2 kilometers from Mo i Rana center. An annual 5.5 million smolt is produced, from 2 plants in the industrial park. The business is owned by fish farmers and has 10 employees.

Land based post-smolt ongrowing will reduce sea period with almost 50 %

Eidesvik Group produces yearly 4500 tonnes  of salmon from their own smolt plant and at four sea sites. To shorten the period at sea, the Group now builds a post-smolt plant of NOK 45 mill. The plant comes with integrated recirculation of water.

“Today the smolt is 100 grams when launched at sea. The growth period before harvest is between 18 and 20 months. If we let it grow 3-5 months in the post-smolt unit it will be presumably 500 grams when put in sea cages. And so the period at sea will be less than one year,” explains Lars Magne Eidesvik of Eidesvik Settefisk, part of Eidesvik Group.

In addition to shorter production time, a large post-smolt will be more robust and less prone to diseases, which leads to lower mortality and higher product quality. The existing smolt plant will supply the fish going to the post-smolt plant, which will have a capacity of 600 000 fisk yearly, in three cycles.

The water temperature in the post-smolt plant will hold between 12 and 16 degrees C, which will ensure good growth. There will be two large fish tanks, five meters deep and 15 meters in diameter. We water treatment will be in a separate building and consist of screen filter and biofilter. To keep the CO2-content down there will be a two-step CO2 removal, which also ensures a low ammonium level. The plant will run on brackish water. The plant will neighbor the existing smolt plant.

The thickening of waste will commence in the center of the fish tank, due to a new hydraulic design and a special outlet solution. The central outlet will have several functions: fish exit, sludge exit and dead fish exit.

“The outlet is supported by a higher turnover of water and is the key to effective capture of concentrated sludge. We have conducted pilot trials of this part in cooperation with the client,” explains Steinar Skybakmoen of Sterner, who will build the tanks and the recirculation system.

The post-smolt plant is number five in a row delivered by Sterner. The buildings will be constructed by local entrepreneurs, under the leadership of Multiconsult, who will design the building.

“The plant will ensure a good total economy through a high feed conversion ratio. It will also ensure a good water quality for the fish and clean tank environment,”  according to Mr. Steinar Skybakmoen of Sterner.

For further information on Post-Smolt, contact Mr Steinar Skybakmoen +47 48 04 72 04  email: