Available in both Standard and Advanced configurations, Marlin+ offers flexibility to suit different operational requirements. The Standard version supports accurate, continuous monitoring, while the Advanced version extends functionality to include process control for aeration, feeding, alarm handling, and other automated tasks. Both versions share the same physical platform, allowing systems to be upgraded as operational needs evolve.

If you’d like to discuss how the OxyGuard Marlin+ could be integrated into your monitoring or control system, get in touch with the Technolab team for practical, application-specific advice.

OxyGuard Marlin + brochure.pdf

If the battery isn’t working correctly, alarms and control functions may not activate when they’re needed most, putting stock and production at risk.

To ensure your system performs as intended, we strongly recommend testing the backup battery during installation and as part of your regular maintenance schedule. Confirming correct operation from day one helps avoid unexpected failures later.

👉 Read more about backup battery testing on the OxyGuard website:

However, the site presented several challenges. The existing ponds were shallow and had not previously been used for barramundi grow-out. Being located in the Arizona desert, the farm experienced extreme temperature changes, very hot during the day and cold at night. These large ambient temperature swings caused significant fluctuations in pond water temperature, which negatively affected fish health and performance.

The Challenge

Barramundi are highly sensitive to temperature changes. Without accurate monitoring, it was difficult for Mainstream to fully understand how daily temperature swings were impacting fish growth, oxygen demand, and overall pond balance.

Mainstream needed a reliable system to:

• Continuously monitor dissolved oxygen (DO) and temperature in each pond
• Provide alarms for low oxygen events
• Log data to better understand environmental trends and improve production outcomes

The Solution

Technolab specified and installed two integrated OxyGuard Pacific systems, each monitoring 12 ponds, across the pond network.

These systems were designed to:

• Continuously measure dissolved oxygen and temperature
• Log data for long-term analysis
• Provide alarms to protect fish health

The ability to record and analyse trends over time was critical, allowing Mainstream to clearly see how temperature fluctuations affected barramundi performance and oxygen demand.

Scott (Managing Director, Technolab) and Tom (Technolab electrician) built both Pacific systems in Technolab’s Hobart factory before shipping them to the United States. Once on site, Scott travelled to Arizona to complete the installation and commissioning.

Research & Development Expansion

In addition to the pond monitoring systems, Technolab installed a separate OxyGuard system to support Mainstream’s research and development program.

Mainstream is trialing alternative grow-out methods using large tanks or raceways buried deep into the sand. This approach allows much greater control over water temperature and offers a potential pathway for more efficient farm expansion compared to traditional ponds.

A long-range Wi-Fi link was established between the R&D site and the hatchery office (over 1.5 km away). This allowed the OxyGuard web interface to be viewed locally, providing real-time oxygen and temperature readings, along with historical logs.

Integration & Connectivity

The OxyGuard systems were fully integrated with Mainstream’s central SCADA platform using MODBUS communication. This integration was delivered in collaboration with Insight Engineering, using the Ignition SCADA system.

As a result:

• Staff in Melbourne can view real-time data from the Arizona farm
• Environmental data from all sites can be centrally monitored
• Farm management decisions are better informed and more proactive

Any post-installation support was handled efficiently using FaceTime, allowing rapid troubleshooting and fine-tuning without delays.

The Outcome

The data collected by the OxyGuard systems has proven invaluable. Mainstream now has clear visibility of pond conditions, enabling better control of oxygen levels, improved understanding of temperature impacts, and stronger production outcomes.

With reliable monitoring, alarms, and seamless SCADA integration, Mainstream Aquaculture has strengthened both day-to-day operations and long-term planning across its US and Australian sites.

Results at a Glance

• 24 ponds continuously monitored, reducing risk of stock loss from low oxygen events
• Improved production consistency through better control of temperature and oxygen variability
• Data-driven decisions using logged DO and temperature trends to optimise pond management
• Reduced labour and manual checking, lowering day-to-day operational costs
• Remote visibility from Melbourne, enabling faster support and oversight across sites
• Stronger return on capital investment by protecting stock, improving growth outcomes, and supporting scalable farm expansion

Native Fish Stockist is a growing Murray cod hatchery run by Kane and his family. Because there were no monitoring systems or alarms in place, Kane needed to live on site to constantly check the tanks and respond to any issues. This meant very long days, interrupted nights, and little peace of mind.

As the hatchery planned a major upgrade to its power and pond aeration systems, the family recognised that continuing without monitoring or alarms was no longer practical. With significant capital already being invested, they decided it was the right time to add a proper dissolved oxygen monitoring and alarm system.

Kane was already familiar with Technolab and OxyGuard, having previously purchased portable meters from us, so he reached out to discuss a more permanent solution.

The Challenge

Through several phone conversations, Scott identified that the hatchery required a full monitoring and control system across 16 tanks.

To clearly understand the site layout and operating needs, Scott and Kane completed a virtual walk-through of the farm using FaceTime technology. From this, Scott determined that the OxyGuard Pacific analyser would best meet the hatchery’s requirements.

Once the scope was agreed on, Technolab worked closely with Kane to plan:

• Sensor locations in each tank
• Cable runs and junction box placement
• Integration of emergency oxygen dosing

Custom oxygen distribution panels, controlled by the OxyGuard system, were designed and built in Technolab’s Hobart warehouse.

The project was delivered in three key parts:

1. Continuous dissolved oxygen measurement in all tanks
2. Automatic emergency oxygen dosing if levels dropped too low
3. Alarm notifications via audible alerts and SMS messaging

The Solution

After being built and tested in Technolab’s Hobart workshop, the complete system was shipped to Native Fish Stockist’s Beechworth facility.

Installation was completed over four days by Scott, working alongside Kane’s brother, a licensed electrician. This approach allowed the hatchery to continue operating with minimal disruption.

The Outcome

With the new monitoring and alarm system in place, Kane and his family no longer need to live on site around the clock. They now have confidence that any issue will be detected immediately and that they will be notified straight away if action is required.

Most importantly, they can finally enjoy a full night’s sleep, knowing their fish and their business are protected 24/7.

Equipment list

Hatchery-

1 x Main unit, 4 x Combi Units for up to 20 sensors

30 x Relays and 30 x Digital I/O's available for PID oxygen control, setpoint emergency oxygen, pressure, level and flow switches etc

16 x DO/Temp measurement with PID oxygen control (16 x Relays, 16 x Analogue Sensor inputs)

4 x Emergency Oxygen outputs ) to control 4 Tanks (4 x Relays)

2 x Heated tank temp probes (2 x Analogue Sensor Inputs)

16 x Tank Level Switch (16x Digital Input)

1 x Air flow (Pressure) Switch (1 x Digital Input)

3 x Water flow Switches (3 x Digital Input)

3 x Supply tank level, Low and High level switch (6 x Digital Inputs)

Alarm Light and Siren (2 x Relays)

SMS Module for alarm Notification (SIM Card Plan required)

Web Interface & Cobalia Access(12 months cloud data) (Access to internet/network required)

We’re excited to announce that we’ll be showcasing the Marlin+, OxyGuard International’s latest innovation in aquaculture monitoring and control, at the upcoming Australian Prawn Farmers Symposium, taking place from 6th – 8th August at the Amora Hotel, Brisbane.

What began as early conversations with farmers about the future of water quality monitoring has now become a reality. The Marlin+ represents a significant step forward in smart oxygen control, designed to deliver greater insight, more adaptive management, and enhanced precision for farm operations.

Developed by the expert team at OxyGuard International, this next-generation technology offers aquaculture professionals a new level of control and data visibility to support more efficient, responsive, and sustainable farming practices.

📍 Visit our stand at the Symposium for an exclusive first look at the Marlin+ in action.

We look forward to connecting with producers, researchers, and industry leaders to discuss the latest in aquaculture technology and innovation.

See you in Brisbane.

Spending time with Paw and his team was both insightful and inspiring. We had the opportunity to learn more about their new range of ozone sensors for aquaculture, as well as gain a deeper understanding of Cobalia. The time spent exploring how OxyGuard continues to advance ozone solutions to support effective water treatments was truly invaluable.

What stood out most was the passion and dedication of the OxyGuard team. Their commitment to innovation in the aquaculture industry, and their warm friendship, made this visit particularly special.

We’re already looking forward to the next trip to celebrate 35 years of industry collaboration. Here’s to continued partnership and progress! 🐟🌊

#Aquaculture #OzoneTechnology #Innovation #Partnership #Sustainability #OxyGuard #Cobalia

With over 35 years of research and innovation, Tritonlux has established itself as a leader in UV disinfection technology and we’re proud to represent their solutions in our region.

Being chosen to support the Tritonlux range is an honour, and we look forward to building a long and successful relationship together.

Here’s to raising the bar in water quality, safety, and innovation! 💧✨

Scott will be on our stand, ready to showcase how our OxyGuard and Hydrotech products can take your facility's processes to the next level. Whether you're looking to optimise water quality or streamline operations, we’ve got the solutions to help your business thrive.

Surrounded by top experts in the aquaculture field, this event is a prime opportunity to connect with industry leaders from around the globe. 🌍 Don’t miss out on the chance to engage in insightful discussions, discover the latest innovations, and expand your network.

👉 Ready to join us? Click here to register and learn more about the conference.

We look forward to connecting with you there!

Ozone has been used to purify water since the early 1900's, initially to treat municipal wastewater. Eventually, it was introduced as a water treatment system used in aquariums, swimming pools drinking water, industrial process water and fish farms producing fish for human consumption.

Ozone is a powerful oxidizing agent that effectively targets organic matter, viruses, bacteria and parasites. It also targets off-flavour compounds, such as geosmin, and may introduce a new way to avoid the expensive and time-consuming purging of fish grown in recirculating aquaculture systems (RAD). Ozone rapidly decomposes and turns to pure oxygen, giving rise to additional benefits in both the water environment and biofilter.

Research evidence has shown ozone provides promising advantages for water treatment in RAS facilities

To continue reading this article click on the link below

In 1993 I was living on the Gold Coast working in the hospitality industry, which I still have a great passion for. John rang and offered me a position working with him at Technolab which he had just started.  I said I would give him 12 months and here I am, 30 years later, Managing Director and still loving what I’m doing! 

My commitment and passion to working with our clients to help them achieve the right outcomes for their projects is my driving force and I am lucky to love what I do. My focus when putting a system together is that it is easy to use and the most important consideration of all is that it is installed well.  We know that OxyGuard products are the best in the industry, so our main focus is that functionality is key to the system.

Working exclusively with teams from OxyGuard International in Denmark and Hydrotech Sweden for 30+ years has seen our business build a great network of support and trust with our suppliers.

I am incredibly proud of the small business and brand that is Technolab. 

We have built strong relationships with our industry partners Ben Pope and his team from Fresh by Design and have worked on many projects overseas with Rod Missen from RAD AQUA.  They build the big systems and we come in and work our magic to build monitoring and filtration systems that have been based on the customer’s needs for their facility.  It is great to work with other successful Australian companies who can come together and share ideas to develop new ways to assist our customers achieve their outcomes.

When I need time out you can find me spending time with my family, drinking many a good coffee from my local, on the golf course or floating down the river on my boat, fishing. 

Water mostly contains dissolved oxygen and nitrogen. But if the water becomes oversaturated, your fish can develop Gas Bubble disease. To detect and prevent that, you need a TGP probe.

The probe measures temperature and TGP – Total Gas Pressure, which, together with a DO probe and a control system, can calculate and display the saturation of oxygen and other gases. With this information, you can stay informed and ensure the health of your fish.

Contact us if you have questions and we can help to guide you in what is right for your unique environment.