Different fish species and different development stages of fish require different water quality. The general treatment process in a RAS consisting of solids removal and a biological treatment will in many cases suffice with regards the content of particulate matter in the water. However, certain species, and especially the juvenile stages of these might be sensitive to otherwise harmless fine particulate matter.
Ozone in moderation can be very beneficial in a RAS for fine particulate removal. It removes fine and colloidal particles by micro flocculation which then enables removal by mechanical filtration. IAA uses as standard, 40 micron drum filters, which in collaboration with ozonation is very effective in fine particle removal. The water in a RAS can also dis-colored where ozone in moderation will clear this.
It is a policy for IAA not to remove fine particulate in line by particle/sludge entrapment as in stationary filters. This we believe is too risky in relation to the potential for facultative bacteria activity in a bio filter.
We include fine filtration on a side stream of the flow where we can keep the process controllable and quantifiable.