Els Engel

Too big, too many

The catfish are growing

Yesterday we experimented with different techniques to measure our catfish.

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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

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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

With:

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.

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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