How do I use a culling net correctly?

Hi Darrel, Here is a brief description of how to use koi culling nets.

How to use a culling net

This brief article describes how to use a culling net. Not how to cull, but some of the many things to consider when you do culling of your prized new fry.

  • Flip the net around every time you take a new scoop. It will prevent any blockage of the fine net from dirt build-up.

  • Take a quantity of fry that you can view and judge in one go. Not too many or to few. Personal preference and eyesight counts.

  • You should know the culling criteria BEFORE you start. Look at the fry first, take a few scoops, plan what you are going to do. How much you need to keep. Then stick to the plan. (It is variety dependent but rarely you keep more than 25% at first culling. That is 1-2 for every 10 fry!)

  • Keep in mind the outcome. How many space you have for the fry to grow. Estimate how many fry you have, how many space available. Plan accordingly. Vitally important.

  • No use keeping more that your facilities can accept. All will die a horrible death of disease or malnutrition because of your lack of self-control and irresponsibility.

  • Those you keep should be worthy of your criteria, not iffy or maybe.

  • Rest the net on a basin with water so that the fry can swim. Lift the net to view them sideways if necessary or observe with the smaller net.

  • With the smaller net, quickly select those that catches the eye. Discard the rest.

  • You should never start searching for “a last one”

  • To keep 20-40% is normal. Keeping more is criminal. Even prolific varieties like Ogon need culling.

  • If you see something different KEEP IT and see what happens when it grows. Breeders privilege to view a mutant.

  • Count and record what you keep. Count the rejected ones later. Do not keep them alive.

  • Dumping them somewhere in order to keep them alive is a merciless act of suffering with no purpose or merit.

  • Don’t sell rejected fry alive NO MATTER WHAT. Why then cull? 

  • Do keep the water well aerated.

  • Do prevent the water temperature rising by doing frequent water changes and working in the shade. Do not take too many fry in the bowls or nets. They should be hungry and vibrant with life, not lethargic and dying from lack of oxygen. Feel the vitality with your hands and fingers.

  • It is a good idea to do this in salted water (3kg/1000litre) and afterwards a mild anti parasite prophylactic. 
  • When in doubt, call us.


    Happy culling.

    Servaas de Kock