Carrying capacity calculator
This is a range, not a number. The pond's own water sets where it lands, and a pond pushed toward the top of the range needs more management, not less.
Method and sources
predators = 10 to 15% of the total by weight
Standing crop is the weight of all fish a pond holds at once, all species and sizes together. It runs from about 40 lb per acre in clear, infertile water to about 2,000 lb per acre in a fed, aerated pond run like a hatchery, and the answer for any one pond depends on what feeds the food chain. The classes here are bands from the extension tables and forum practice, and the range shown is the band, not a measurement of this pond.
What narrows the range: water visibility, which tracks the plankton bloom (the fertilization calculator reads it by Secchi disk); whether fish are fed pellets and how much (the feeding calculator); total alkalinity, since a bloom needs alkalinity above about 20 ppm to hold (the liming calculator); and aeration, which is what lets a pond carry more than the fed band without a summer kill (the pond aeration calculator). Water quality falls as fast as standing crop rises, which is why the fed and intensive classes carry a warning.
Predators such as bass are 10 to 15 percent of the total by weight, the source of the old rule of about 50 lb of bass per acre in a fertilized pond. Months to capacity is the time a newly stocked pond takes to fill the range, about 18 months in the South and 24 in the North.
Sources: Mississippi State University Extension publication p1428, Managing Mississippi Ponds and Small Lakes (250 to 400 lb per acre of bluegill in a fertilized pond at 18 to 24 inch visibility). Practitioner discussion: Pond Boss forum thread Pond carrying capacity, including the ewest note that natural capacity runs 40 to 2,000 lb per acre and that water quality drops as it rises.