A new plug-and-play filter system recently launched by Israeli tech company BioFishency will allow smaller-scale and developing-world producers to convert their flow-through systems (FTS) to recirculating aquaculture systems (RAS) virtually overnight.

The BioFishency filter removes carbon dioxide and ammonia from the water and enriches it with oxygen for the nitrification process, converting the ammonia into nitrates, creating a system with very low water demand that is closed from the outside environment.

"The majority of companies supplying RAS are targeting high-end product or producers, so smaller, lower values cannot convert," BioFishency co-founder and aquaculture veteran Igal Magen told IntraFish. "With our system, developing-country producers can afford to upgrade."

The system can deal with any species of fish or salinity level -- and has applications either in production, in storage or in live transport. It also has applications in combined closed and flow-through systems, said Magen.

"Say you have extensive fish ponds. You are only doing one cycle per year but attach a closed-system nursery and extend the time the fish spends in there, you can then double production," he said.

Closing off the water supply can also significantly reduce disease and risk of mortality and deliver big benefits.

"Understanding your water quality is a big issue in aquaculture," said Magen. "If you know you have a supply of good quality, clean water, the fish is basically a byproduct."

China first

The first and immediate market for the system, which recently won the inaugural start-up incubator FishTech Awards, is China, where a clampdown on environmental freedoms means there is a "fast and immediate" need for change.

"Many Chinese producers, particularly tilapia producers, are at a point where they have to do something or close the farm," said Magen.

The system is already in operation in a European sea bass and bream farm, in an Israeli hybrid striped bass farm, in several installations in India for barramundi, as well as a Chinese perch farm (the brain child of Spain's Roda International) in Shijiazhuang, an hour from Beijing by train. BioFishency will now also begin trials for use in transporting live clams and lobsters.

Coldwater next

Magen is honest about the limitations of the system, which relies on warmer temperatures to enable the bacteria in the filter to operate. The process also produces nitrate (NO3), so some process of denitrification has to be in place, usually in a separate small reactor.

And while “the technology is affordable, there is a minimum price point at which it generally makes sense,” said Magen, although many “variables come into play in terms of feed, stock, environment and market.”

"If you take catfish,” he explained, “the same species, produced in different countries, will sell for $3 (€2.64) in one market and $6 (€5.25) in another, so there are many variables, but loosely speaking, if the farm gate price is upwards of $2.50 (€2.20) per kilo, then our technology will give a good return on investment."

BioFishency is also working on a variation of the filter that works well with coldwater species. It uses an electrical current in saltwater systems to produce fluorine, which in turn converts ammonia into nitrogen gas. This system needs no additional denitrification process.

But the current system is perfectly suited for the markets in which it is arguably most needed -- developing-world countries with a lack of access to clean water -- and to that end, in Magen's words, the technology has the potential to "change the industry."