Pond Boss Forums STOCKING A NEW POND Creating the food chain Food Chain in a 100% Clay Pond

You're welcome Rod.

How "hot" the treatment pond in the study was depends on how much native fertility there was. The feed itself would create a eutrophic water condition (in a 1 acre pond) but definitely not unacceptable if the native fertility were very low. The feeding rate being ~10 lbs daily of a 32% protein feed. On the other hand, couple the feed nutrients with a native carrying capacity of 170 lbs of fish/acre and then the nutrient mobilization would be hyper-eutrophic. One should keep in mind that the standing weight of fish greatly exceeds what it would be if it were completely dependent on the mobilized nutrients ... roughly double ... and so there is twice as much competition by fish for space and oxygen. In other words, they are under greater risk of tragedy than under the same nutrient mobilization conditions but no feeding (which tragedy is common in hyper-eutrophic water especially without aeration).

There is a lot of freedom for customization ... ranging from very modest where clear water is desired to the very edge of reason for those who cannot get enough or who are never satisfied.

Nutrient mobilization can be reduced by increasing the protein sequestration rate. Essentially this means feeding a feed with a greater proportion fish meal and/or animal proteins. The catfish feed only converts around 13.5 % of its protein to BG flesh. By my reckoning, 40% feeds formulated for BG convert at around 18% of its protein. So this means less protein and thus less nitrogen needs to be added to support the same carrying capacity. The improvement in conversion efficiency results in about a 26% reduction in nutrient mobilization. Equivalent results of the example above would require 7.36 lbs daily or 1325 lbs annually of a 40% feed converting 18% of its protein. At $1.50 per pound .... approximately $2000 per year. At a harvest rate of 365 lbs/acre year the cost per pound of harvested fish $5.47 per pound. That's not bad given that it more than triples the carrying capacity of fish the nutrient mobilization would otherwise carry ... again assuming the basin is of very low fertility. The example of the study should probably be limit that anyone should attempt and only then when aeration is in place. For me, I like something modestly under the middle.