Els Engel

Too big, too many

The catfish are growing

Yesterday we experimented with different techniques to measure our catfish.


Fish in a bowl - To measure it's weight Aleksandra Kalashnikova

A quick calculation told us the catfish are getting too big to be in a tank with this many fishes, but how big are they actually? We tried different methods:

- measuring them while holding them still (more ore less)
- putting them in a bowl of water on a scale
- putting them in a measuring cup, supposing 1 liter of fish is 1 kg of fish
- searching a table with length/weight ratio


Tyler and Robin measuring a catfish - It's a wonder it lies still. They probably had one second to read its length before it started wriggling again. Aleksandra Kalashnikova


When we knew for sure we were right, we transplanted some to the new systems in the greenhouse, so they'll have some more space.


Two tables about width/height ratio European Catfish - Source: Bulgarian Journal for Agricultural Science http://www.agrojournal.org/14/02-11-08.pdf

This is the calculation:
Rule of thumb: 500 gr fish per 20 - 40 liters
Tower: 500 liters
That means: 6 - 12 kg fish per system

Currently: 275 fish per system
1 fish around 50 gr
275 x 50 = 13,7 kg