Point Four MBD Diiffusers

Oxygen and Air Diffusers

Oxygen and Air Diffusers for Hatcheries and Sea

With summer fast approaching, it’s all the more important to ensure you have sufficient aeration in your tanks or sea pens Having efficient and reliable oxygen and air diffusion is the key to manage your stock and your costs.

At Sterner we have a wide range of ceramic diffusers and our hugely popular RSB6 self weighted rigid diffuser, ideal for sea and loch pens.

Microbubble Diffusers

Pentair Point Four microbubble diffusers use a specially developed, ultra fine pore ceramic plate that produces a cloud of extremely fine bubbles of approximately 100–500 microns; far superior to airstones, porous hose or membrane type designs. The flat plate design ensures uniform bubbles across the entire surface and minimises bubble coalescence to achieve an absorption rate in excess of 80%, depending on depth and flow rate. Bubbling Pressure is 25 to 35 psi. (1.7 to 2.4 bar).

Sterner RSB6

The RSB6 diffuser has been specifically designed to introduce air into farm cages located in open water. It has been built to deliver optimum performance and withstand the harsh conditions of sea water with minimum maintenance. The RSB6 is constructed of a strong, woven polyester fibre material with an operating range of 1.2 – 3.6 cfm and comes complete with 3/8” stainless steel hose tail, making it extremely durable.

The bespoke self-weighted and rigid design of the RSB6 allows for optimum use of aeration in the cage. Compared to previous methods of aeration the RSB6 is extremely efficient at producing bubbles, which creates a curtain effect when the unit is installed horizontally. The deployment and removal of the RSB6 diffusers is straightforward with a bespoke, non-corrosive, fish friendly RSB lifting sling


Choosing the right Dissolved Oxygen Meter

What Do I Need to Know Before Purchasing a Dissolved Oxygen Meter?

So, you've decided you need a dissolved oxygen meter to monitor oxygen levels for your fish pond, hatchery or sea site.   Perfect, here are some things for you to consider;

  1. What parameters do you want to measure? It sounds obvious when choosing a DO Meter, but is it just dissolved oxygen you want to measure.  For most trout ponds and hatcheries, dissolved oxygen and temperature are the key parameters to monitor.  Our aquaculture industry leading OxyGuard Polaris, Polaris 2 and YSI Pro20 DO Meters are perfect for ponds and hatcheries
  2. Is your water only fresh water? Ponds and Hatcheries are most commonly fresh water, but there are several which will have sea water, water with a saline content or even some tanks with fresh water and some with salt water.   Knowing the salinity of your water, can affect the dissolved oxygen reading on your meter and can even have an affect on the quantity of feed used and costs associated.  Our OxyGuard Polaris units, offer a manual salinity compensation.  If you need to monitor both dissolved oxygen and salinity, the YSI Pro2030 is a single handheld instrument with allows you to measure dissolved oxygen, temperature and conductivity.
  3. What other parameters do you need to measure?  It's become very common to want to measure more than just dissolved oxygen and temperature in recent years, with a significant rise in measuring pH both in hatcheries and at sea.   For header tanks, Total Gas Pressure (TGP) has become important in addition to just dissolved oxygen.
  4. I'm needing to use a handheld monitor at sea. Our range of handhelds are ideal for use both on land based farms and at sea.   Our YSI Pro SOLO range is ideal for use on sea sites and challenging environments.   The YSI ProSOLO ODO/T offers a modern solution for dissolved oxygen and temperature, using optical probes, thus reducing maintenance, whilst the YSI ProSOLO ODO/CT monitors dissolved oxygen, temperature and conductivity.  You can read more about the YSI ProSOLO range here.
  5. How do I capture my data?  Pencil and paper are still popular, but somewhat old hat and can lead to data being "fudged".   The Polaris 2 range of DO and TGP Meters offer a USB download to Windows PCs, as do the YSI ProSOLO ODO/T and ODO/CT handhelds
  6. I want to monitor multiple parameters, what's the best way to do this?  This depends entirely on personal preference and your budget.   If you like the OxyGuard Handy range on instruments, then you need to be prepared to accept multiple instruments.   This has positives and negatives, positives being that the cost of servicing and repair can be less, and you can have multiple people taking different parameter readings.   The YSI Pro DSS offers multiple parameters, in a very customisable way.   The ProDSS with parameters from dissolved oxygen, ph, ORP, Turbidity, Ammonia, Ammonium, Nitrate, TDS (Total Dissolved Solids) and many more.
  7. I've chosen a meter, how do I look after it?  All our dissolved oxygen meters come with instructions for use and how to maintain, but we all break things.   At Sterner, our Service Centre of manufacturer trained and accredited engineers, provide annual servicing and calibration certification for OxyGuard and YSI instruments.

What's our most popular Handheld Meters? Our most popular meters for hatcheries and ponds is the OxyGuard Polaris, ideal for monitoring dissolved oxygen and temperature.   For sea sites, the YSI ProSolo ODO/CT measuring dissolved oxygen, temperature offers a robust and versatile meter for challenging environments.

Ecosoft P’URE AquaCalcium reverse osmosis filter

Ecosoft P’URE Reverse Osmosis Systems

Sterner are delighted to bring the EcoSoft P’URE Reverse Osmosis Systems to our range of residential Reverse Osmosis Systems.

Ecosoft P’URE AquaCalcium Reverse Osmosis Water Filter

AquaCalcium is a replaceable filter with mineral granules. The mineralizing filter is designed in such a way as to ensure the speed of the flow of water is like that of natural mountain springs. As a result, the calcium content is always maintained at 55-65 mg/l.

Who are its users?

Ecosoft P’URE AquaCalcium reverse osmosis filter is designed to purify drinking water to ideal quality in homes with up to 5 people. Calcium-enriched water is suitable for people of all ages, as it allows a person to receive the optimal daily amount of vital calcium.

Stages of Filtration

Tap water first passes through three pre-treatment replacement filters. They intercept mechanical pollution (rust, sand, silt and others), chlorine and its compounds.

The 4th step is the membrane, which at the molecular level purifies water of 99.8% of impurities, including bacteria and viruses.

Purified water after the membrane enters a special AquaCalcium replacement filter for the first mineralization stage. The technology of the filter simulates the natural rate of passage of water through rocks. Due to this, the time of contact of water with the natural mineral of the AquaCalcium replacement filter increases, ensuring effective mineralization.

Then the water is collected in a storage tank, from which it passes to the second stage of mineralization in the AquaCalcium replacement filter.

This design allows you to preserve the necessary and constant calcium content in the purified water.

The final stage is a coal post filter designed for final water purification. It contains high-quality activated carbon from coconut shell, which corrects the taste and smell of the purified

You can find out more about the Ecosoft P’URE AquaCalcium RO System here.


Ecosoft P’URE reverse osmosis filter with mineralisation

Ecosoft P’URE with Mineralistation RO (reverse osmosis) technology allows to remove from water 99.8% of contaminants. This is the most reliable way to purify drinking water, available for home use.

280 l/day Dow Filmtec™ RO membrane is the core part of the filter. It purifies water at the molecular level, removing all pollutants, including chemicals and germs.

The reverse osmosis membrane is a semi-permeable polymer fabric. Its pores are 200 times smallest viruses, which guarantees complete biological protection. The water purified in such a way does not need sterilisation. It is completely safe for people of any age, including small children.

Who are its users?

Ecosoft P’URE reverse osmosis filter with mineralization is designed to purify drinking water to ideal quality in homes with up to 5 people.

Water with calcium is suitable for people of all ages.

The process includes pre-treatment (3 steps), reverse osmosis, post-filtration and saturation of water with minerals.

First stage

Removes large (more than 5 microns) particles of mechanical impurities (silt, sand, rust, scale).
Replacemet filter media – polypropylene fiber.

Second stage

Neutralizes chlorine, organic and organochlorine compounds (pesticides, dioxides, etc.). As a result, the taste, color and odor of water is improved.
Replacement filter media – granulated activated carbon produced by Calgon Carbon (USA).

Third stage

Fine cleaning of mechanical and organic impurities.
Replacement filter media – activated carbon-block.

Fourth step

Reverse osmosis. The pre-cleaned water under pressure is passed through a membrane. Purified water is fed to the next stage of filtration, and pollution that has not passed through the membrane with some amount of water is discharged into the sewage.

Fifth step

Post-carbon cartridge (water conditioner). Absorbs the gases dissolved in water and gives the water a pleasant, natural taste.
Replacement filter media – activated carbon from coconut shell.

Sixth Stage

The mineral filter. Saturation of water with the optimal composition of minerals and trace elements.

You can find out more about the Ecosoft P’URE with Mineralistation here.

7 Stage Reverse Osmosis

What Do I Need to Know Before Purchasing a Reverse Osmosis System?

What Do I Need to Know Before Purchasing a Reverse Osmosis System?

So, you've decided to get serious about researching Reverse Osmosis Systems before making a purchase. Perfect. Here are some more things to consider:

  1. Do I need to buy a tap? RO systems require a separate tap for the treated water to dispense. Did you know you can upgrade your RO faucet to match the colour, finish and style of your existing kitchen sink fixtures?
  2. Wondering how many stages of filtration an RO system should have? RO systems typically come in 5, 6 or 7 stages of filtration. At least 5 stages is typically recommended for most applications.   Our 6 stage system adds a re-mineraliser to which enriches water with elements such as calcium and magnesium.   Our 7 Stage system adds a further Ionizing cartridge to this process.
  3. If you're on well water or an area with high levels of sediment, you may want to consider a system that has extra pre-filtration (5 stages). Our Aquafilter RO systems will provide adequate filtration for most applications, but you might want to consider an additional pre-filtration system.
  4. What about water hardness? Does incoming water have a hardness level above 7 grains per gallon (gpg)? Keep in mind that an RO system is not a water softener and if your water is above 7 gpg hardness, water softener pretreatment will help preserve the life of an RO system and membrane, although not required.
  5. Does an RO System Waste Water? Similar to how we use water to wash our dishes, clothes or vehicles, RO technology uses water to clean the RO membranes as they process water. During the filtration process, RO systems typically use more water than the filtered water it produces. But because the system shuts down once the storage tank is full, water does not continue to run down the drain. Some systems are more water efficient than others. If this is a concern, check out the APURE SENNA nero Reverse Osmosis System.
  6. How much water can a system produce? Expect a GPD (gallons per day) production rate of 50% to 75% of system GPD rating. While it's true that no one really uses 50+ gallons of drinking water per day, the “50 GPD rating” is the speed that an RO system makes drinking water and actually produces a gallon of water per hour (with normal water pressure of about 60 psi). Thus, a 50 GPD-rated system will provide adequate production for the common household and will not cost much more than a lower GPD-rated system.
  7. Would you like RO water for your ice maker? Add a refrigerator icemaker adapter kit to easily get RO water from your icemaker. You'll no longer need to buy a separate refrigerator filter.

What's our most popular RO system? The most common system purchased by customers is the Aquafilter 7 Stage Reverse Osmosis System due to great value, made in the EU, simple installation, and quick release filters for easy filter changes.

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.