Best aeration for fresh water fish culture

Fish culture in India is of various species – Tilapia, Mangur, Rohu, Catla, Mrigal etc. Most are fresh water fish and are mouth breathing, so it seems that when one does fish culture, there is not much need of artificial aeration. Considering the low density of farming and species of fish, as well as the long duration of growth, natural aeration is sufficient in many cases.

However, there are many times when artificial aeration is needed for even fish culture. Some of these situations can be:

  • High density fish farming where the density of fish is many times than what is found in its natural habitat
  • Requirement of faster growth and large weight of the fish in a shorter time
  • Balancing various parameters like pH, ammonia, phosphates, nitrates, nitrites, etc.

With low Dissolved Oxygen (DO) in the water, fish growth will slow down. The water parameters that oxygen helps regulate by oxidation – often called the Chemical Oxygen Demand (COD) will also suffer. As a result the sludge, extra feed, waste, nitrates, hydrogen sulfide, phosphates, ammonia etc. will not breakdown further and cause problems in the water.

Low dissolved oxygen would be first seen as increased time taken to finish the feed by the fish. Later one would notice that the fish are not increasing their feed intake and finally one would notice that the fish are not growing as expected. In the meantime if there is a disease, it will spread very fast due to low immunity of the fish. With low DO there is a high chance of infection and even the entire culture failing.

Although aeration and high dissolved oxygen in fish farming is important, the biggest challenge is that the cost of production needs to be very low. The price of fish and its fluctuation and long culture periods do not allow for high costs of aeration.

So a good aeration system for fresh water fish farm would need to be low cost as well as efficient.

One of the best methods for fish culture is diffused aeration. With this method the bubbles from the bottom of the pond or tanks provide high DO across the tanks or pond.  When tanks are used for fish farming – whether regular or biofloc fish farming (BFT), AirOxi Spider is often used because it is the most convenient and easy form or aeration.