Hi Hans.  I'm a W&WW ...

Hi Hans.  I'm a W&WW professional who has run an aquaculture design company.  I recommend a case by case approach considering water quality, species, climate, nature of hatchery / grow-out operation (e.g., degree of recirulation, water supply, etc.).  I favour biological treatment that generates biomass that can be used at the facility, preferably to reduce feed costs, improve sustainability, etc.. There is a need to design an aquacuture specific treatment system to suit the site characteristics.  If recirculation is involved, the sensitivity of the product becomes a major / key design criteria.  Just framing the topic.  Thanks for raising the question and look forward to more specific queries.