How ozone works in aquaculture
Ozone delivers four distinct benefits in aquaculture water. First, pathogen inactivation: at properly-controlled doses, ozone destroys viruses (including IHNV, VHSV and Nodavirus), bacteria (Vibrio, Aeromonas, Yersinia, Renibacterium) and parasites (sea lice, amoebic gill disease) that would otherwise circulate endlessly through a RAS. Second, organic oxidation: dissolved organic carbon (DOC) from fish waste and feed is broken down into smaller, more biodegradable molecules that the biofilter can process — preventing the brown 'tea-coloured' water typical of un-ozonated RAS. Third, micro-flocculation: ozone causes fine particles to aggregate, allowing them to be removed by drum filters and protein skimmers that would otherwise miss them. Fourth, taste improvement (for harvested fish): ozonated water removes geosmin and MIB that cause off-flavours in farmed fish.
RAS (Recirculating Aquaculture Systems)
RAS systems demand the highest level of water-treatment integration in aquaculture. A typical RAS treatment loop includes drum or belt filtration for solids removal; a biofilter (typically moving-bed or fluidised-bed) to convert ammonia to nitrate; degassing for CO₂ removal and O₂ supplementation; ozone treatment for pathogen control and DOC oxidation; a residual ozone reaction tank; quenching (typically with sodium thiosulphate or GAC) to remove residual ozone before the water re-contacts fish; and pH and temperature control. Our role is to design and supply the ozone module of this loop, integrated with the biofilter and degasser controls. Get the dose right and the RAS thrives. Get it wrong and you damage gills or kill the biofilter — both of which we are constantly engaged to help operators recover from after they've bought cheap ozone equipment elsewhere.
Hatcheries and quarantine systems
Hatchery water must be effectively pathogen-free. Egg and larval stages are extraordinarily vulnerable to bacterial and viral infection, and a single pathogen breakthrough can destroy a season's production. We supply ozone-based hatchery water treatment for finfish, shellfish and crustacean hatcheries, with residual-ozone quenching tuned for the sensitivities of larval life stages. Quarantine facilities — used to hold and treat incoming broodstock or imports before they enter the main system — use ozone as the primary disinfection barrier, often in combination with UV, to ensure the main population is never exposed to imported disease. Our protein skimmers (IPS series) are widely used in marine hatcheries to remove the organic load that ozone helps create.
Marine aquariums and public aquaria
Public aquariums face the same water-treatment challenges as commercial aquaculture, plus the additional requirement that the water must be crystal clear for visitor experience. Ozone is the foundation of marine aquarium life support, removing the organic load that causes yellowing and turbidity while disinfecting recirculating seawater. Our work in this segment includes Reef HQ and a range of other aquatic display facilities. The IPS protein skimmer range is specifically engineered for ozone-injection in marine recirculating systems, with corrosion-resistant materials throughout and standard sizes treating water flows from 10 to 100 m³/h. Salt-water aquaria require ozone-compatible materials throughout — we don't cut corners on this and have systems running for 15+ years in continuous marine service.
Safety: residual ozone and fish welfare
Ozone is highly toxic to fish at concentrations well below those used for water treatment. Residual ozone reaching fish tanks at >0.01 mg/L can damage gills; at >0.05 mg/L it is acutely lethal. This is why ozone treatment in aquaculture MUST be designed with a properly-sized reaction tank (typically 15–30 minutes contact time) followed by an active quenching stage and online residual-ozone monitoring with hard-wired interlock that halts ozone dosing on any residual breakthrough. Cheap aquaculture ozone systems frequently lack proper quenching or monitoring — when something goes wrong, the operator only finds out when stock is dying. Every system we design includes redundant residual-ozone monitors, automatic dose shutoff, and an emergency quenching reservoir.
