Oxygen is one of the main parameters concerning fish health welfare. In intensive farming it is important that adequate levels of oxygen can be maintained at all times in the fish tank to optimize feeding, welfare and growth. Low or Medium Head Oxygenators are normally the preferred choice in our designs. In this way we do not need an extra pumping step and are still able to supply the oxygen in an efficient way.
The Medium Head Oxygenator (MHO) is invented by ACE and utilizes the static water pressure of the fish tank to increase the water’s oxygen uptake. The entire water flow is passing the oxygenator. Inside the reactor the oxygen passes multiple chambers which results in efficient oxygen use (>90%) and optimal mixing. The MHO dimensions depend on the flow rate of the system, the MHO used to be cylindrical but recently also square shaped MHO were developed. The MHO normally has an inlet oxygen concentration of 7-8 mg/L and an outlet concentration of 16-24 mg/L. The head loss over the MHO is in the range of 20-50 cm.
Low head oxygenators (LHO) may be chosen if it is not possible to place the oxygenators at a depth of 2-4 meter below the water surface of the fish tanks. This is often the case in existing concrete raceways for trout farming or in locations with a rocky substrate. LHO’s have the disadvantage that outlet concentrations of oxygen are limited.