Importance of Sorting Fish

Ok, it’s been 3 weeks since you bought your juvenile from the seller and you’ve not done anything with them? You just kept the fish in the same pond you poured them into since the first day? Well, you are doing something wrong.


The first thing you need to do after the like 3 weeks of stocking your fish is to find the time to sort your fish no matter the tight schedule you have.

Here is the thing, depending on the farmer that supplies you fish, there is always inconsistency in the size of the fish you have on the farm, so in order not to lose a lot of your fish, it is important to sort the fish at intervals.

if you’re about to start a fish farm or have started a fish farm but want to improve your fish business skills, continue reading this article cos it will help you a lot get through some difficulties of the business especially for those of you that don’t know how to sort fish.

Importance of Sorting Fish

I know you’re wondering why should I sort my fish and if I don’t what are the implications of this? Well, there are some things that you will not be told and if not careful, you’ll learn the hard way.

I don’t want you to fall victim to ignorance because you were not told, that’s why I’m writing this article to give you an update on the reasons why you should sort your catfish regularly.

1. To Prevent Cannibalism

The first reason for sorting catfish at any stage you might think of is to avoid cannibalism.

Catfish are carnivorous which means they eat each other, so if you don’t sort them into the right sizes, the bigger ones will eat the small ones and vice versa.

Cannibalism reduces the quantity of your fish which reduces your profit and can lead to loss, for you to reduce this on your farm, constant sorting is the way to go.

Even if you stock the same size of fish (which is not always the case), some fish will grow faster than the rest, so you need to sort such fish out and put them into another pond at intervals.

2. Improve Fish Efficiency

The second importance of sorting fish is to better improve fish efficiency. The thing is there are some farmers that once they stock their fish, don’t bother looking back to see what is happening in the ponds. It is one thing for the fish to not eat themselves, it is another thing for the fish to perform well.

Mixing fish of different sizes without sorting affects their growth and development.

Let me break it down for you, if there are bigger fish in the pond than smaller ones, the smaller fish will not be able to eat well cos they’ll be overshadowed by the bigger fish which in turn affects their performance and efficiency.

That is why I always tell new farmers to make sure that at least they should sort their fish every 3 weeks or one month except if you’re farming in an earthen pond which does not require constant sorting like other artificial types of ponds.

How To Sort Catfish

There are different ways you can use to sort catfish at different times and stages which they are.

You can either use the manual, semi-automatic, or automatic method of sorting.

Although the automatic way is always expensive cause you’ll need to buy high-level equipment to carry out this task and if you’re not running a VERY LARGE SCALE commercial farm, it will be a waste of money.

For this article, we’ll be focusing on the manual method of sorting our fish.

Regardless of the stage of your fish, it is required to use a sorting table or sorting board to carry out the process.

A sorting board/table is one important piece of equipment you must have on your farm, it can either be made of wood or aluminum depending on your location and pocket.

Below are the steps to how to sort catfish on your farm:

i. Drain out the water from the pond

ii. Pack the fish with a dragging net or a scooping net (depending on the size of the fish) into a barf

iii. Make sure there is water in the barfs where the fish are going into.

iv. Add a little palm oil to the barf to prevent the water from foaming which could in return affect the fish.

v. Using a sorting table (board) or grader, separate the fish into different sizes

vi. After sorting, carefully return the fish of the same sizes to their respective ponds.

vii. Top the water of the ponds where the fish are to the desired level

NOTE: Before returning the fish to the ponds, make sure you clean the ponds and add fresh water to them.

When you want to sort your fish using a sorting board, sprinkle a little water on the board you’ll be using to sort so that it doesn’t dry up thereby causing trouble for the fish when sorting.

Remember, catfish are aquatic animals.

Materials Needed For Sorting Catfish

Sorting Board

Even if you’re running a small-scale fish farm or a large-scale farm, there are materials necessary to carry out a seamless sorting process. Some of the materials needed are but are not limited to:

i. Barf or basins

ii. Scooping net or dragging net

iii. Sieve

iv. Scale

v. Salt

vi. Palm oil

vii. Sorting board/table and grader

vii. Stool or chair

Before using any of the equipment, make sure you sterilize the equipment, and salt bath the equipment to avoid transferring bacteria to the fish when sorting.

Best Time To Sort Fish

One of the most common questions farmers ask when we talk about sorting catfish is when is the best time to sort fish?

There are many theories different people around the world practice when it comes to sorting catfish when they’re smaller (like fingerlings or juvenile) and when they’re slightly bigger (300g or melange and above).

One of the best practices that I do which you should follow is sorting your fish either in the morning (before 10 am) or later in the evening (after 4 pm).

These times are the best to avoid stressing the fish. I do my sorting very early in the morning (as early as 6 am), this will help me round up before the morning sun starts hitting hard.

One rule of thumb any time you want to sort your fish is not to feed them.

Feeding the fish before sorting the fish will cause constipation which will lead to throwing up and in the long run lead to their death.

I believe you don’t want to pack so many dead fish every time you sort fish on the farm.

How Often Should You Should Sort Fish

Depending on the quality of fish, sizes of fish amidst other factors, every two weeks if they’re fries or pre-fingerlings; every 3 – 4 weeks if they’re at fingerlings and juveniles, and maybe every month once they are over 300g.

Although things do change depending on how well you take care of your fish, you might need to sort the fish before the stipulated time mentioned above or might not even bother to sort them if they’re growing at the same pace.


It is important to know how to sort fish and carry out the task at intervals as mentioned in the article.

To recap, below are the importance of sorting catfish:

i. To prevent cannibalism

ii. To improve efficiency

Take it slow, and don’t rush things if you’re not getting things when sorting your fish, don’t worry, you’ll get it right one day.

I always tell my mentees, your first two production cycle is for learning and making mistakes as fish farming is not a get-rich-quick scheme.

If you stock your fish, practice constant and moderate sorting and you’re just a step further to becoming a guru.

Cheers to your SUCCESS.


Please enter your comment!
Please enter your name here