September 22, 2020
Nigerian Catfish Farmers
Importance of PH for Water Quality in Fish Farming.
Fish perform all their bodily functions in water. Because fish are totally dependent upon water to breathe, feed and grow, excrete wastes, maintain a salt balance, and reproduce, understanding the physical and chemical qualities of water is critical to successful fish farming. To a great extent water determines the success or failure of an fish farming operation.
Very high (greater than 7.5) or very low (less than 6.5) pH values are unsuitable for most aquatic organisms. Young fish and immature stages of aquatic insects are extremely sensitive to pH levels below 6.5 and may die at these low pH values.
High pH levels (7.6 - 14) can harm fish by denaturing cellular membranes. Changes in pH can also affect aquatic life indirectly by altering other aspects of water chemistry.
Low pH levels accelerate the release of metals from rocks in soil or sediments in the stream.
These metals can affect a fish's metabolism and the fish's ability to take water in.
High pH Levels Effect
At high pH (>7.5) most ammonium in water is converted to toxic ammonia (NH3) which can kill fish.
Moreover, cyanobacterial toxins can also significantly influence fish populations.
NOTE: One critical parameter is pH:
Not only for the health of the fish, but for the bacteria have that pollute the water as well as nitrifiers that remove excess nutrients.
pH is important in fish farming as a measure of the acidity of the water or soil.
Fish cannot survive in waters below pH 6.5 and above pH 7.5 for long periods.
The optimum pH for fish is between 6.5 and 7.5.
Fish will grow poorly and reproduction will be affected at consistently higher or lower pH levels.
Death is certain. Bad water ph is 80 % responsible for mist death in catfish rearing.
