Barbel grow well in running and stillwater so long the water quality is satisfactory (O2 levels over 50% saturated) and food is abundant. In our ponds, our young barbel grow at a rate of about 2% body weight a day at temperatures over 12oc . The optimum temperature range is 16 – 20 oc.
So in these optimum conditions, a 10 gram fish (4″) will grow to about 75 grams (8″) after 100 days and up to 1kg after a further 150 days. 250 good growing days with temperatures averaging 16oc represents about 2 summers of growth in our climate!
Once the fish reach this body weight their growth slows down and realistically you can expect a maximum growth of just 1% a day in an optimum environment. So a double figure fish (4.5kg) is possible after a further two summer’s growth. These growth rates represent a guideline based on high oxygen levels, optimum food availability, no stress and temperatures averaging 16oc. In a stillwater fishery environment this is possibly over optimistic.
However, many fishery owners report back growth rates close to this and the fasted double figure fish reported back to us from 4″ has been 6 years.