Our main focus of research is aquaculture, or the farming of aquatic organisms. People are often surprised that aquaculture is viable in dry southern Alberta. The secret is to reuse the water over and over again. An offshoot of this water reuse is our aquaponics (the growing of plants in fish water) research, which began in 2003.
Our main facility is a modern, high-intensity recirculating aquaculture system that loses virtually no water (98 per cent recirculating). The only time water is lost is when it is used to wash the drum filter, which removes particles bigger than 62 microns (for comparison, one micron is 1/1000 of a millimetre).
After passing through the drum filter, the water enters a fluidized sand bed. This sand bed works as a biological filter where bacteria convert ammonia in the water into nitrate. This is an important process as the ammonia that the fish produce becomes toxic if it is allowed to build up in the water.
Next, the water passes to a low-head oxygenation unit where carbon dioxide is removed and oxygen is added. The oxygen is produced by a vacuum pressure swing absorption (VPSA) oxygen generator located just outside the main facility.
The VPSA generator separates the oxygen (21 per cent) in the air from the nitrogen (78 per cent) by passing the air through a molecular sieve. The flow of air is reversed every few seconds to exhaust the nitrogen, which moves slower than oxygen. This process produces 95 per cent pure oxygen. The remaining five per cent is argon, an inert gas that is present in air at about one per cent and moves through the sieve at the same rate as the oxygen.
Once the oxygen has been added to the water, it is returned to the fish tanks where the process begins all over again.
A key feature of intensive aquaculture facilities such as ours is continuous and rigorous monitoring. Our system is monitored by a multitude of sensors that measure a variety of parameters, including:
- water temperature
- oxygen concentration
- pH levels
- water levels
The entire monitoring system is connected to a computer that automatically notifies the facility manager if there are any deviations in the monitored parameters that are outside the normal operating range.