News features and technical articles about the evolution of aquaculture, one of the world’s fastest growing industries.

biofilter

Aquafeeds

Biofloc and clear-water RAS systems: a comparison

This study compared two types of indoor, shrimp culture systems: clear-water RAS and biofloc systems. Clearwater RAS had the edge in water quality, but shrimp in the biofloc treatment had a higher feed conversion ratio. 

Responsibility

For the future, a feed that makes fish feces float?

German researcher believes that floating fish feces – stemming from cork used in feed blends – would help recirculating aquaculture systems more efficiently remove suspended solids. The big question is, will feed manufacturers get on board? 

Health & Welfare

Biofilter inoculation in recirculating aquaculture systems

Biological filters are essential parts of recirculating aquaculture systems that transform toxic fish compounds such as ammonium and nitrite into less-harmful nitrate. The authors tested the convenience and efficiency of three methods for the initial inoculation of aerobic biofilters. 

Innovation & Investment

Estimating biofilter size for RAS systems

Controlling total ammonia-nitrogen (TAN) concentrations is the primary concern when sizing a biofilter for use in a recirculating aquaculture system. Sizing decisions are best based on previous experience with a given biofilter media in a specific biofilter configuration. 

Innovation & Investment

Recirculating aquaculture technology, part 2

To start a biofilter together with a source of nitrifying bacteria, you must provide the conditions that will encourage the growth of the bacteria. The basic process requires initial preparation of water chemistry, adjustment of alkalinity to support bacterial growth 

Innovation & Investment

Recirculating aquaculture technology, part 1

Biological filtration is one of the critical required unit processes in recirculating aquaculture systems. Non-corrosive filter media with large amounts of surface provides area for nitrifying bacteria cells to colonize. 

Innovation & Investment

Low-space bioreactors remove ammonia in recirculating systems

Despite their relatively small footprint, low-space bioreactors deliver sustainable and cost-effective biological wastewater treatment, particularly in recirculating aquaculture systems, where ammonia removal is critical.