“High re-use” without biofilter – Alternative to RAS?
Alvestad Marin has launched an “almost RAS” concept that can greatly reduce water usage. We have chosen to call it “high re-use” without a biofilter. Efficient CO2 and particle removal is put in the driver’s seat, at the same time as we rely on research and tone down the problems surrounding the accumulation of ammonia compounds.
There is currently great interest in land-based fish farming, and many are considering building new facilities. As a result of new technical requirements, there are also a number of established facilities that are planning upgrades in the near future. If one does not have unlimited access to water, it will be natural to consider solutions that provide opportunities for increased production capacity and better utilization of the water source as part of the upgrade.
In the following, we embark on a small experiment where, with the help of a few robust systems, we can manage a recycling rate of as much as 90-95%.
In short, the following water treatment processes are used:
• Oxygen addition
• CO2 removal with stable high efficiency over time
• Particle removal
• Temperature control / energy system