Waste Water Management In Fish Farming

Waste Water Management In Fish Farming
Waste Water Management In Fish Farming

In Fish farming, Waste Water Management must be taken seriously. Waste water odour was vividly one of the reasons we had to stop catfish farming in my parents’ residence while growing up.

The bad smell the neighbours complained of whenever we release waste water for a cleaner one became unbearable but of course, they were very justified!

Our catfish pond was a concrete pond even though the construction of one of the ponds was not done very well; long story there. The water was changed every two weeks and of course into the street drainage even though dad later had to dig a soak away for the pond; to stop the flow into the neighbours gutter, the smell was just not as bad.

Waste water from our fish ponds coupled with other reasons such as selling to traders who use their own scale, buy at ridiculous rates and the children moving to boarding houses outside town, we had to stop the catfish farming. The two concrete fish ponds are still lying fallow; maybe I should just find a use for it.

Waste Water Management In Fish Farming
An Abandoned Fish Pond

There are several fish farming businesses that have shut down due to complaints from people in the environment especially when it is in a residential neighbourhood; and they are of course justifiable claims.

Regardless of where a fish farm is located, there are ways of managing the waste water without polluting the air as the smell can linger for up to 24 hours.

Waste water management especially in concrete fish ponds are common necessity because the fishes need clean water at least once in a week for their overall health and development.

A proper drainage system in such environment means that houses as far as 10 poles away would also perceive the odour from such waste water.

Waste Water Management In Fish Farming
Catfish In A Concrete Pond

In environments without a proper drainage system, the waste water when released will become soaked in the soil; if the soil is not clayey though, the environment can become water-logged. This means the waste water can allow mosquitoes and other flies to breed causing more issues.

This problem of waste water disposal is not an impossible task and it has a lot to do with the type of pond in place. I stated earlier that one of the fish ponds in my parents house wasn’t properly constructed as we only had the water released into the available drainage system initially.

The construction of a concrete fish pond especially in residential areas should be done to meet the standard by having a waste water outlet that will lead directly to a stream or a waste tank where it would not cause problems for neighbours.

Causes Of Waste Water In Fish Farming

As a fish farmer, it is important to have an expert in the field who can help out on fish farm management practices including disease control and medications. The construction of a fish pond is not exempted and should be done by an expert and not just done with having an idea of what a fish pond looks like.

The experts that can help in starting a fish farming business include veterinary doctors, a zoologist, an aqua culturist or someone who has experience rearing the specific type of fish farming about to be started.

A catfish farmer is best for a catfish farmer not a catfish farmer for a tilapia fish farmer; they may both be fish farmers but the fishes do not exactly behave the same way. 

Fishes are water organisms meaning they live in water as their sole habitat. In the wild, the fish live in flowing waters meaning their waste water flows and fresh water flows in again whereas in a concrete pond, the waste water do not flow out unless released by the fish farmer.

Waste Water Management In Fish Farming
Fish In The Wild

Construction of a fish ponds mean using stagnant water to raise fish and still have the fishes healthy. This directly implies that the waste from the fishes, remnants of their food and other form of waste mixes with this stagnant water and can make it quickly unsafe for the welfare of the fishes in captivity.

The turbidity of the water in the fish pond is a way to know when the water is due for a change although changing the waste water can be done once in every 2 weeks.

It is important to pay attention to the water in the pond so they don’t become too dirty or until the odour is really bad before changing the water.

Waste Water Management In Fish Farming

Waste water is inevitable in a concrete fish pond and will occur every two weeks regardless of the farmers choice or not. Managing the waste water however, goes a long way both for the fishes, the fish farm business as well as the environment.

Several factors should be considered and good fish farm practices put in place in other to reduce or probably eliminate the bad odour from the waste water in the fish ponds.

Good Water Quality As A Way To Manage Waste Water Odour

The primary habitat of the fish is definitely the water implying that at all times, they are in the water. The colour of the water tells a lot about the health of the fish available in such ponds.

Adequate knowledge of water parameters can help farmers understand the fish mechanisms and how water quality influences the fish behaviour.

Waste Water Management In Fish Farming
Mortality In Fish Farming

Another reason why a fish expert is needed is to avoid mortality in the fish output and likely weight reduction. Some farmers have done everything possible but still record loss because they do not pay enough attention to the water; fish farming is not just about feeding the fish!

Being in captivity, the fishes defecate and also feed in the same water reducing the quality of the water each time they do the needful. This simply put, the overall health, growth rate and productivity of the fish is affected by the water in their ponds.

The water quality parameters include: temperature, pH level, dissolved oxygen, and ammonia. When the water is not of good quality, the feed given to the fishes are eaten but do not convert into flesh or additional weight resulting in low weight and sometimes, mortality.

Waste Water Management In Fish Farming
Thermometer For A Fish Pond

Temperature In Good Water Quality

Fish are water organisms meaning they are cold blooded and would not survive in warm or hot environment. How the fish will react in cold water (early mornings) is different from how they will react in the afternoons; as a matter of fact, they do not play around but retire to the bottom corners of the pond.

The water temperature for a fish pond is between 260C to about 320C for maximum overall health and functions. They can eat and play at this temperature range resulting in higher growth rate.

Temperatures below 150C can result in stress, infections and the fish stops growing and ultimately die off because the waste are not dissolved reducing the oxygen available. Warm temperature has just about the same effect; the temperature just has to be right.

pH Level In Water Quality

The level of hydrogen ion present in the water is referred to as the pH. For fishes in captivity, the pH should be between 6.5 and 7.5. Water pH levels lower than this especially as low as 4, may not kill the fishes but will increase their stress and cause a slow growth.

Waste Water Management In Fish Farming
pH Scale For Fish Pond

When pH increase to about 11, the water becomes acidic as the ionized ammonia becomes incredibly low killing the fishes. This is something many fish farmers don’t understand. The water pH has to be right and can be checked with simple equipments available at affordable rates.

Dissolved Oxygen (DO)

Knowing the dissolved oxygen level can be a little tricky but not impossible. This can be observed as the water bubbles the fishes produce when they move around in the water or when they are being fed.

When the fishes don’t eat well, you can guess that the oxygen level is low. The low feed can make the dissolved oxygen low as well and fishes need the oxygen to stay alive just like humans. Dissolved oxygen level should be 4mg/liter.

Fish would experience an extremely slow growth rate because the feed conversion ratio drops and this means a fish that should be harvested at 5 months resembles a fish of 3 months meaning more feed, low yield and ultimate loss for the fish farmer.


The waste water produced by a fish pond can be ultimately dependent on the quality of water in the fish pond.

Water quality parameters when observed and taken into consideration by adhering to the range acceptable can go a long way in reducing the odour of the waste water.

Waste Water Management In Fish Farming
Waste Water Management In Fish Farming

Releasing the waste water from the fish pond can be done without the environment getting polluted.

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