How To Know the Number of Fishes A Pond Can Take?

Fish in ponds 2

This singular question or issue can make or mar a fish farm business. Overstocking of fish ponds has been the detriment of many fish farms in Nigeria. Here is how to know the number of fishes you can put in your fish pond. Do you just gauge with your eyes that the pond can take 1000 fishes or 2000 fishes?

Imagine you put 20 children in a small face-me-I-slap-you kind of room. That’s overpopulation. In fish parlance that is what we call an excessively high stocking density.

Issues that shouldn’t normally occur would arise. Water to bathe would be scarce. The toilet and other facilities would be strained. Diseases would thrive and easily spread.

There would be competition for food and afterwards, the bully of the house would be clearly identified.

He would continue getting the best food, be bigger and stronger to continue his bullying. However, imagine if they were just 2 fishes in that pond? (Yes, it is fish we were talking about all along, what were you thinking?)

fish in concrete
fish in concrete pond

What is a fish pond carrying capacity?

Every pond has what is called a carrying capacity. What this means is there is a maximum weight of fishes that the pond can support.

Once the weight is achieved the fishes would stop growing. The weight in that tank cannot exceed the carrying capacity. For instance, you know this white iron tanks?

Bamidele at the farm learning how to use tanks to farm

It contains 1000 litres of water. With an average calculation of 10 litres to 1 fish, that means it can only support 100kg of fish.

What this means is that if you put 1 fish in there, all other factors being equal, the fish can continue growing till it reaches 100kg in size. If you put 2 fishes there, they’ll grow till they each reach 50kg in size. so this tank can take 50-100 fishes if you want them to grow optimally to table size.

The total weight of fishes in that pond sustainably can only peak at 100kg. If you put 100 fishes in there, they would grow till they reach 1kg each in size. If some of them have to continue to grow bigger, then some of them would have to die. You’ll just notice that all the total weight of fishes in the pond doesn’t exceed its carrying capacity.

This carrying capacity can only be calculated not from the dimensions of the pond, but from the actual litres of water that is put in the pond. Don’t forget that you wouldn’t fill the pond up with water to the brim. So for better results, you need a bigger pond.

Items to tick before you stock your pond

Here are some tips that should guide you before you can calculate the stocking density of the fish pond based on the following formula’s for you to know what quantity of fish you should put in your fish pond.

1. Water management: How available is water on the site? Can it be changed quickly, regularly and frequently? How many thousands of litres are you able to pump in and how long that takes? This would let you know if you can plan to change water daily, and therefore stock more. However, if you have to change the water every 3 days, you would have to stock less.

2. Management ability: How many staff do I have on the farm, how skilled are they? How efficient are they? Should 1 person take care of 10,000 fishes?

3. Power availability: You probably need power to change the water in your ponds. This can either be government supply or a generator and fuel. These are costs that should be factored in. If we cannot have access to power to change the water more frequently, then we should stock less.

4. Your financial Power: How many fishes can you raise? If you budget N450 to raise a fish to table size of 1kg (this is only possible using local feeds – for more advise on fish feeds check here), how many fishes would you be able to raise conveniently without running out of funds? We all know that one fish farmer who is looking for quick sales because he cannot afford to feed again and thus gets swindled by fish buyers because of his desperation. Why not stock what you can afford to raise without borrowing money, and start the marketing of your fish 2 weeks before you run out of feed.

Calculate the number of fishes you can put in your pond

After this, you can then use the following formulas to calculate how many fishes your pond can take.

This varies from pond to pond. Different stocking densities for different pond rearing systems. You can read up on the FAO’s stocking density here. All calculations are in meters.

  • For the Earthen Ponds: Length * Breadth * Height *2/5 (Measurement in Feet)
  • The Mobile fish Pond: Length * Breadth * Height *5/3 (Measurement in Feet)
  • Concrete Pond: Length * Breadth * Height *5/3 (Measurement in Feet)
  • For the Tanks: Use the FAO standard of 10 litres to 1 fish at your peril. Experience shows that the fish always hangs when you use that stocking density. That is why most people you see want to sell off thier plastic tanks. For tanks, I would advise you use use a standard of 50  litres per fish.
Fish in ponds 2

Let me give you a free tip, watch this video where I explain how to start your fish farm right.

For more on what you need to know before you start your fish farm project click here

To know how to identify the best fingerlings or juveniles to stock on your farm click here.

You can reach Akinfish at any time on 08161385163 for ideas or counsel, you can also ask your comments or questions in the comment section.

69 thoughts on “How To Know the Number of Fishes A Pond Can Take?”

  1. Dear AkinFish,
    Thank you for all your kind enlightenment on fish farming. Please, I have a question:

    kindly help to advise what the practical number of bags of feed / per month / per each of the growth stage (fingerling, juvenile, grower, semi adult, table size) of 100 catfish should be.

    Please, I need it to calculate what my financial requirement shall be per 100 cstfish from fingerling to tablesize per month.

    Thanks and God bless you all.
    My regards

    1. I stoked 2,000 fingerlings last week but av been losing at least 30 daily, either swollen stomach, wounds on their fins and gills or whitish skin

    1. Dear coach, thank you for your efforts to help us grow. When you say I quote: “For tanks, I would advise you use a standard of 50 litres per fish.” That means 1000ltrs capacity tank can only support CONVENIENTLY 20 fishes. Please confirm.

    2. Dear coach, thank you for your efforts to help us grow. When you say I quote: “For tanks, I would advise you use a standard of 50 litres per fish.” That means 1000ltrs capacity tank can only support CONVENIENTLY 20 fishes. Please confirm.

  2. Good job sir,
    You articles have enriched my knowledge of fish farming, please how much do you charge for consultancy fees.

      1. Thanks for this educative article. I’ve tried contacting you on WhatsApp, but it’s like the number you shared isn’t on WhatsApp. Please send your WhatsApp contact let’s talk business. Regards.

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  4. Thank you for this article. I am blessed by it. By a way of introduction, I am a plant breeder by profession. I have some questions to ask you.
    (1) from my readings from the internet, I saw that a standard fish pond is 1ha or 10000 sq metres. I feel that this is too big. What do you say?
    (2) what will be the length and width?
    (3) what is the dept
    (4) the volume of water.
    (5) the number of fishes it will contain (the stocking rate.
    We want both earth pond and concrete ponds.
    We are targeting 500, 000 catfish, actually our target is one million.
    Finally can you give an alternative area.
    Waiting to hear from you.
    Thank you

  5. Wow, am really happy to read this your article, am about to start a fish farm (concrete) infact the bricklayer will soon through with it and am plan to stock up to 5000pcs with this your article I think I need to stock less.
    God bless you

    1. You are welcome. It is always better to start small and grow, rather than start big, fail and not have the strength to try again ! Lets talk if you have any other challenges !

  6. Ejiofor Ugwoke

    Thank you for the wealth of information shared, I am truly grateful.

    Please I wish to inquire, do I need to change water in an aerated concrete fish pond? If yes, how often?

      1. Ozota Ikechukwu

        I love this post, it’s quite encouraging to starters, I will like to come over and see you one on one, show me your address please.

  7. Thanks AkinFish, you really did a wonderful job explaining all the points in detail. I’m so excited reading your post.

      1. Greetings.
        Please make it simple.

        What length and breadth of a pond with sufficient water is okay for 1000 fish?
        More so, I don’t understand the measurements given above.

        Only two value is given for the dimensions of the pond whereas there are three dimensions ie the height, the legnth, and the breadth, but only 2/5, or 5/3

  8. Akinola Olugbenga

    God bless you for this information, infact I got the information right it’s educative for us that just want to start fish farming. Have been looking for how to know how many fishes can fit into 1000ltrs tank. My question is like how much will I need to feed 100fishes to maturity, say like five to six months.

  9. Thank you sir for the knowledge shared I am about to start dis business and I want to know the number of fingerling a 2000 and 5000ltr tank can take . God bless you for me

      1. I stoked 2,000 fingerlings last week but av been losing at least 30 daily, either swollen stomach, wounds on their fins and gills or whitish skin

  10. Igboanugo Uzochukwu

    Good evening sir
    Sir the size of my pond is length 10ft deepth 3ft width 5ft total of 3 concrete fish pond. What the number of fish that I will grow to table size..

  11. I want to enter into fish farming, i have purchased tapulune measuring 4ft width by 10ft length and 4ft depth. How many cat fish can i farm with it?

  12. Helo sir. Thank you, I so much appreciate this information but I will appreciate you explain this better; “Concrete Pond: Length * Breadth * Height *5/3 (Measurement in Feet)” do you mean 5feet by 3feet and the Height please?

  13. Idahosa ogismien

    Sir , l just started a catfish farming for one month and 300 fishes have died so what can l do. My name is ldahosa ogiamien. Email Prince I dust

  14. Eduke bridget

    Very rich article. I have a concrete pond of 2 by 2 by1 for length width and height respectively . How many catfish should I put and what quantity of water from fingerlings to adult. Thanks in advance.

  15. Thanks Sir
    For the rich enlightened, please with concrete pond size of 4½ by 6 fit and 4½ fit deep,how many fish can be train to table size on it,and how many bags of feeds can be predict,.
    sir thanks

    1. With current feed rates. 600naira per fish is a good budget to raise fish to 1kg size. I am sure that my article has helped you know hot to calculate the fish cost.

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  17. Thank you for this great information…
    If I may ask
    A pond of 15x10x4 ,how many fish will it stock .
    I got 1000 aftery calculation using your formula for concrete
    Does it means is stocking 1000 fishes?

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