for the IRGA it is recommended to measure DC concentration levels
in typical high density production systems. The IRGAs with a
DC range of 0–1% should be sufficient for systems where CO2 levels
are expected to be fairly low, i.e, hatchery or nursery systems,
broodstock holding units, or quarantine facilities. The head space
unit with the IRGA is a satisfactory method for measuring the total
dissolved carbon dioxide in a flowing stream of seawater with the
precision and accuracy required to maintain the culture of fish in
an aquaculture system. In time and with experience, the aquaculturist
should be able to predict upper levels of CO2 concentration
for healthy fish culture based on loading densities, feed rates, flow
rates, and other variables once a number of readings have been
obtained. The head space unit and CO2 probe thus allows the workers
to quickly recognize irregular functions of their RAS as indicated
by high CO2 readings due to any number of causes such as pump
failure, too high a density, poor water flow, inadequate degassing,
etc., and provides them a tool to measure and respond accordingly