Sizing and aeration system for aquaculture water treatment

Aeration & Oxygenation systems

Environmental & sustainable water treatment

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Sizing an aeration system for aquaculture Aeration homepage

Aquaculture system water temp below 20 degC
number of diffusers 6.2.10 require per 10 tonnes (10,000kg) of stock water temp above 20 degC
number of diffusers 6.2.10 require per 10 tonnes (10,000kg) of stock
tank /cage system pond system tank / cage system pond system
Salmonids / trout in tanks/raceways 6 4 8 6
salmonids in sea cages 1 2
Tilapia 1 2
Shrimps (monodon) 1 2

Diffuser codes 6.2.10, requires an air flow of 10 cubm/hr of air and will deliver on average 500g to 1000 g per hour of oxygen. In seawater systems, or if the salinity of the water is over 15 ppt, then bubble size is smaller and oxygen transfer efficiency is higher. The above table should be used as a guideline, if you would like a Dryden Aqua to access your requirements please provide as much information about your facility as possible.

The air blower should be a 100% oil free positive displacement unit, such as a roots type blower operating at a maximum of 1 bar pressure. Actual operating pressure will be a function of hydrostatic heads. Typically the operating pressure is 0.5 bar and and oxygen transfer is 5 kg of oxygen per kilo-watt of energy expended. The Dryden Aqua fine bubble air diffusers generate a mass vertical movement of water, oxygen transfer therefore relates the diffusion through the bubble, but also transfer from the surface. With paddle wheel aerators or surface aerators, apart from the initial transfer of oxygen to the water, there is little transfer or vertical mixing of the water. For very large ponds, a combination of paddle wheel aerators for horizontal flow and fine bubble air diffusers for vertical mixing can prove very effective.

Efficiency & sizing of system

The efficiency of an aeration system is related to a number of key environmental parameters. If you wish Dryden Aquaculture to determine your farms aeration requirements some basic information is required of your facility, please answer as many of the questions given below;
Provide a schematic plan of your farms showing tank spacing
Dimensions of tanks
Water depth
Species of fish/crustacean
Water flowrate through the tanks
Type of enclosure, e.g. earth pond/concrete/fibreglass
Maximum stocking density
Maximum size of the fish
Maximum water temperature
Details on water quality
Soft or hard freshwater, or sea-water
Source of water e.g., spring/borehole/river/lake
Detailed water analysis of water if available
Salinity of the water

Aquaculture system	water temp below 20 degC number of diffusers 6.2.10 require per 10 tonnes (10,000kg) of stock		water temp above 20 degC number of diffusers 6.2.10 require per 10 tonnes (10,000kg) of stock
	tank /cage system	pond system	tank / cage system	pond system
Salmonids / trout in tanks/raceways	6	4	8	6
salmonids in sea cages	1		2
Tilapia		1		2
Shrimps (monodon)		1		2