We attended the World Aquaculture Society (WAS) meeting in March 2025, learning a lot about Recirculating Aquaculture Systems, their requirements and their infrastructure. This helps set the needed capabilities of instrumentation.
Typical water quality recommendations for recirculating aquaculture:
Total ammonia nitrogen (TAN) <1 mg N/liter
Nitrate 0-400 mg/L
Nitrite <1 mg/L (this in many ways sets a goal for our systems)
pH 6.5 to 8.5
Reference: Timmons/Guerdat/Vinci, Recirculating Aquaculture 4th edition, Ithaca Publishing Co. and many oral talks occurring at this meeting.