4.1. Main issues of RAS systems
As reported, solids management and biofilter operation and management are the most difficult tasks in a RAS, constituting the main reasons for system failures. Treatment technology is developed already but how to integrate it all together in the optimum way is likely missing. Rather than looking for better and more complex designs which can often be more difficult to manage, the necessity is to understand which factors are key in each particular system (e.g. fish requirements, energy requirements, water availability). Accordingly to McKindsey et al. (2006), in order to understand each system’s limits, it is required to define physical,
environmental, production and social carrying capacity issues; this argument will ensure consistency in meeting the required sustainability needs of the commercial production systems using RAS.