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Balance for
optimal growth

Aqua Balance System

Franzefoss Minerals delivers end-to-end systems that promote stable pH values in hatcheries adapted to our customers’ processes and available space – which have been specially developed for hatchery fish and optimal water quality. The system automatically mixes lime in the ratio required to achieve the correct pH value.


Franzefoss Minerals and quality of raw materials

Franzefoss Minerals is a marketing company that sells raw materials and products from its own facilities and from other companies in the Franzefoss Minerals Group. We produce lime and dolomite products from local deposits.

As an important supplier of lime and dolomite, we aim to be a market-leader in our field. Lime and dolomite are used in a number of important processes and represent some of society’s most important raw materials. Key application areas include agriculture, industry, building and construction, pH-regulation and cleaning/purification. We also export high volumes to relevant markets abroad.

Our production plants are located close to the deposits with good transport links throughout Norway. Our facilities and companies can be found all the way from Ballangen in the north to Tromøysundet in the south. Our raw materials are of the highest quality, in particular from Tromsdalen, where the lime content exceeds 98.5 per cent. This quality makes it highly suitable for a number of purposes, in refined form as either quick lime (calcium oxide) or slaked lime (calcium hydroxide).

Creating added value

Lime as a raw material

Lime is an inexpensive and naturally occurring product that Miljøkalk produces at our own facilities.


Limestone, or calcium carbonate (CaCO3), is a type of rock that is found all over the world. It belongs to a group of rocks called carbonates, which primarily contain minerals with carbonates (CO3-2).


Lime is a collective term for calcium carbonate (CaCO3), calcium hydroxide (Ca(OH)2) and calcium oxide (CaO). Calcium carbonate (CaCO3) is found in natural deposits. To make calcium oxide (CaO), limestone is heated to high temperatures. When water is added, heat is generated and the calcium oxide becomes calcium hydroxide (Ca(OH)2), also known as “slaked lime” or “hydrated lime”.

At Miljøkalk, we have our own EN ISO 9001 laboratory for quality control of our products. We have accumulated a huge database of historical measurement data that provides in-depth knowledge and confidence in our products. This contributes to flexibility and rapid follow-up of any customer enquiry locally in Norway. We work closely with the Norwegian Institute for Water Research, with an unwavering focus on optimal water quality for smolt and for the process leading up to smoltification.

Lime milk

Lime generates added value for our customers: As a natural product, lime helps stabilise pH values in hatcheries and to neutralise CO2 produced by the fish, in addition to being environmentally friendly.

Lime milk is slaked lime dissolved in water. It acts as a strong base that easily increases pH values. In addition to the pH effect, slaked lime reacts with CO2 to form calcium bicarbonate. This is extremely beneficial for the production of smolt as it increases the buffer capacity without a notable increase in CO2 levels. This provides a good production environment, an effect you do not get with lye (NaOH).

The Aqua Balance System can be adapted to customers’ individual needs with regard to space utilisation and other wishes. The Aqua Balance System is a system that controls lime logistics, pH and dosing of lime milk in the process water of RAS facilities or other types of facilities. The system is closed, dust-free and reliable. An accurate system that is gentle for fish and safe for operating personnel, with a focus on minimal manual handling of chemicals.


Using lime in hatcheries is a safe, simple and effective way to ensure optimal conditions for smolt. We process, store, transport and fill your silo or warehouse. As Miljøkalk has local production plants here in Norway, we can use the Agri Balance System to safeguard quality, efficiency, logistics and – not least – the environment.

Water quality

Franzefoss Minerals’s system deliveries enable our customers to achieve optimal water quality and the correct pH value for smolt.

The water quality in hatcheries is critical for the fish’s health and well-being, and therefore also for the quality of the smolt. Neutralisation of CO2 and proper nitrification with a consistent water quality play an important role in optimising water quality which in turn affects the nitrogen cycle. It is also important to ensure consumption of alkalinity during nitrification.


Lime as a pH-regulating substance

One of the ways Franzefoss Minerals exercises its corporate social responsibility is by focusing on environmentally friendly products. Lime is a natural product extracted from limestone. Limestone is formed in two ways: organically and inorganically.

The organic method is more common and occurs when shells and corals sink to the bottom of shallow water and are later covered with sand and silt. Pressure and temperature then result in the formation of limestone.

With more than one million daily users, lime in its various forms is one of the most common natural products in Norway. Lime is a naturally occurring chemical that is cheaper to use than other pH-regulating substances.

Lime contributes to a safer working environment than other comparable – often chemically manufactured – substances.

And end-to-end pH-regulating system

Franzefoss Minerals delivers end-to-end systems that promote stable pH values in hatcheries adapted to our customers’ processes and available space – which have been specially developed for hatchery fish and optimal water quality. The system automatically mixes lime in the ratio required to achieve the correct pH value.

AquaPlus H for RAS systems

A common feature of all recirculation facilities for hatcheries is that they purify and recycle much of the water. Up to 99%. Water from the breeding vats, where fish live and eat, is first mechanically filtered through a filter belt or filter drum to remove large particles.

The water then undergoes biological treatment to purify it of carbon matter (organic materials) and harmful ammonia (ammonium nitrification). This stage uses a bio film culture that rests on a solid or suspended plastic substrate.

This oxidises the ammonia to form less toxic nitrites and then harmless nitrates.

The biological stage is often combined with the venting of carbon dioxide.

In the next stage, the water is disinfected using ozone, oxygenated and returned to the fish vats.

There are two main reasons for using AquaPlus H in hatcheries.

  • To neutralise CO2 produced by the fish’s metabolism after consuming and processing feed.
  • To consume alkalinity and produce

CO2 in the nitrification stage / biofilter The majority of the carbon dioxide derives from the fish’s metabolism and is directly proportionate to the feed intake. This factor is likely to be around 0.8 tonnes CO2/tonne of feed. The biological stage produces protons (acid) that react with bicarbonate in the water to reduce the alkalinity or the water’s buffer capacity.

If this process goes too far, it can result in dangerous pH reductions that will harm the fish. This is where AquaPlus comes into play. AquaPlus H is added to the water and dissolves in calcium ions (Ca2+) and hydroxide ions (OH-). These will in turn react with incoming CO2 in the water to form bicarbonate which then increases/stabilises the pH value.

AquaPlus H offers multiple benefits. In addition to being a high-quality product produced in Norway, it costs much less than other pH-regulating compounds, and is much better for the environment.

AquaPlus H has a detoxifying effect on copper, and slaked lime is also believed to positively impact the smolt’s survival rates when they are released into the sea.

Entire value chain

By entire value chain we mean from the moment we collect the lime until you achieve a stable pH value. Miljøkalk supplies high-quality systems with traceability in all stages. We extract, refine, store, transport and fill our customers’ depositories with lime. Our facilities include a silo for storage, production and mixing of lime milk, dosing stations and control systems.


Miljøkalk constantly focuses on development and expertise. To this end, we develop our products in close collaboration with national and international R&D resource pools. Miljøkalk is a member of Norwegian Water, which is a not-for-profit stakeholder organisation for the Norwegian water industry.

The organisation helps to live up to its vision of ensuring clean water by securing the industry favourable framework conditions and facilitating expertise development and knowledge-sharing. The organisation is owned by the Norwegian municipalities, municipally owned companies, municipal operational assistance organisations and some private cooperative water works.

Other activities

Miljøkalk has extensive experience of working with specialist contractors and suppliers of instruments, electrical systems and automation, transport and logistics and water analyses.

We also have our own Group laboratory.

Partnering with Miljøkalk

Over almost 100 years in the industry we have accumulated extensive expertise and unique knowledge of system deliveries, specialising in areas such as using lime milk to achieve correct pH values.

Finance and agreements

Miljøkalk delivers end-to-end lime milk systems adapted to our customers’ processes and available space. Our facilities are use well-known technology and tried-and-tested components to guarantee a stable system.

Miljøkalk’s system deliveries are designed to be simple, secure and stable, yet also flexible. This is why we offer agreements to cover differing needs

Under a five- or ten-year agreement Miljøkalk will carry out a main annual service tailored to the age of your facility. The agreement covers all standard working parts, and the costs are allocated evenly over the term of the agreement to provide

predictable finances. We will deliver a status report on the facility after completing your service.

Support agreements can also incorporate operational monitoring, where Miljøkalk remotely monitors the facility and receives any alarms. By including lime deliveries in the support agreement you can be sure that your silo will never be empty, as we will arrange new deliveries as required. A support agreement will give you access to buffer inventories of critical parts stored close to Gardermoen Airport for rapid delivery. Our support agreements also provide free phone support 24 hours a day.

Miljøkalk can offer various financing solutions in partnership with our bank. These will be tailored to suit individual customers. Please contact us if you require further information.


Why choose Franzefoss Minerals?

Miljøkalk supplies end-to-end systems that ensure stable pH values, focusing on simplicity, security and stability.

With almost 100 years’ experience in the industry, we are represented along the entire value chain. Miljøkalk extracts, refines, stores, transports and fills customers’ depositories with lime. Our end-to-end lime systems are adapted to our customers’ processes and available space. Our facilities are designed to be installed in coastal conditions and specifically to minimise maintenance time and to maximise uptime.

The lime we use undergoes quality controls during production to ensure a purity of more than 98.5 per cent.

Our deliveries include a support/service agreement. This provides access to buffer inventories of critical parts from our stores in Norway, along with 24-hour telephone support.

Kontakt oss for befaring og uforpliktende tilbud

Sven Fürstenberg
Markedsansvarlig Vann & Miljø
tlf. +4748142557
phone +4748142557

Ole Petter Andersen
Prosjektleder Teknisk salg
tlf. +4795216086
phone +4795216086

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