Commercial Recirculation Systems


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Commercial Recirculation Systems

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The system

The recirculation of fish culture water is relatively straight forward task to achieve where water reuse is less than 90%. However where there is more than 90% of the water reused, or if the system is 100% closed then more complex water processing is required to give a tighter control over the system. This section presents a brief description of recirculation systems. The other sections on this web site describes the individual components making up the recycle systems in more detail.

The construction of a recycle system involves selecting the components in the following flow diagram . Installation of the filtration component involves locating on a concrete pad and connection of services. The service to comprise of electrical connection and pipe connection.

Fish tanks The water flows out of the fish tanks by gravity flow through channels and into the sedimentation tank. Care should be taken to insure that there is no solids break-up

Sedimentation The heavy solids are removed in this tank

Conveyor filter The conveyor filter removes all of the solids greater than 100 microns at up to 450 cubm/hr without breaking up the solids. This means that the solids are removed from the water without releasing proteins, fats and lipids. This feature dramatically reduces the load of the system. This task can not be achieved by filters such as drums and vertical screen that are more aggressive on the soft fragile faecal pellets.
The water passes through the filter by gravity flow and is picked up by pumps and sent to the biofilters/

Biofilter Trickling down-flow biofilters ( 100, 200 & 300 cubm/hr), remove dissolved nutrients such as ammonium from the water. The biofilters also aerated the water and blow off carbon dioxide. Oxygen can be injected directly into the biofilters.

AFM pressure filter The Advanced filtration media pressure filter removes all particles from the water down to 5 microns. This filter provides a dramatic improvement over conventional pressure sand filters. Water flowrate 100 cubm/hr

Ozonation The ozonation system conventionally treats 10% to 20% of the total recycled water. Systems to cope with water flowrates up to 500 cubm/hr are available.

UVc disinfection A range of UVc units in titanium, stainless steel and plastic are available for water flowrates up to 200 cubic metres per hour. All of the water passes through the UVc units

Pumps The water is returned to the fish using 4kw pumps that deliver 100 cubm/hr at 10m head

Temperature Control of water temperature heating and cooling depending on the species

Oxygen monitoring Intensive systems should all have oxygenation and oxygen monitoring

Oxygenation Diffusers should be used in the tanks, the biofilters can be used as oxygen contactors, an active oxygenation system ( 1.5kw) can also be employed for flows of 500 cubm/hr

Telemetry There can be as many as 100 float switches, sensors, oxygen probes and temperature probes etc on a system. The telemetry system monitors all of these inputs and provide vital management facilities.

Sizing the system

If you know what water flowrate and biomass of fish you wish to support, the components and the cost of the system can be determined from this web site. However if you have please let us know if you wish clarification.

Fish tanks	The water flows out of the fish tanks by gravity flow through channels and into the sedimentation tank. Care should be taken to insure that there is no solids break-up
Sedimentation	The heavy solids are removed in this tank
Conveyor filter	The conveyor filter removes all of the solids greater than 100 microns at up to 450 cubm/hr without breaking up the solids. This means that the solids are removed from the water without releasing proteins, fats and lipids. This feature dramatically reduces the load of the system. This task can not be achieved by filters such as drums and vertical screen that are more aggressive on the soft fragile faecal pellets. The water passes through the filter by gravity flow and is picked up by pumps and sent to the biofilters/
Biofilter	Trickling down-flow biofilters ( 100, 200 & 300 cubm/hr), remove dissolved nutrients such as ammonium from the water. The biofilters also aerated the water and blow off carbon dioxide. Oxygen can be injected directly into the biofilters.
AFM pressure filter	The Advanced filtration media pressure filter removes all particles from the water down to 5 microns. This filter provides a dramatic improvement over conventional pressure sand filters. Water flowrate 100 cubm/hr
Ozonation	The ozonation system conventionally treats 10% to 20% of the total recycled water. Systems to cope with water flowrates up to 500 cubm/hr are available.
UVc disinfection	A range of UVc units in titanium, stainless steel and plastic are available for water flowrates up to 200 cubic metres per hour. All of the water passes through the UVc units
Pumps	The water is returned to the fish using 4kw pumps that deliver 100 cubm/hr at 10m head
Temperature	Control of water temperature heating and cooling depending on the species
Oxygen monitoring	Intensive systems should all have oxygenation and oxygen monitoring
Oxygenation	Diffusers should be used in the tanks, the biofilters can be used as oxygen contactors, an active oxygenation system ( 1.5kw) can also be employed for flows of 500 cubm/hr
Telemetry	There can be as many as 100 float switches, sensors, oxygen probes and temperature probes etc on a system. The telemetry system monitors all of these inputs and provide vital management facilities.