Fertilization calculator
These are per-acre rates from the extension tables, scaled to the pond. They assume a bass and bluegill pond at least three feet deep over most of its area. Judge each application by the visibility reading, not the calendar.
Method and sources
Season total = 8 to 12 applications
Start when the water stays above 60 F in spring. Make three applications two weeks apart to start the bloom, then apply again whenever a Secchi disk or a white object on your arm disappears deeper than 24 inches. Skip an application when visibility is under 12 inches; that bloom is dense enough to crash and pull oxygen down at dawn. Stop when the water cools in fall. A typical season runs 8 to 12 applications.
Do not fertilize when total alkalinity is under 20 ppm; lime first, because phosphorus is tied up in soft water and the bloom will not come. Do not fertilize a muddy pond (plankton needs light), a pond with rooted weeds or filamentous algae over much of it (the weeds take the nutrients), a pond that is rarely fished (more fish only means more to manage), a pond with steady outflow (the fertilizer leaves), or a pond used for swimming or as a drinking source.
Rates and schedule from Mississippi State Extension publication p1428, Managing Mississippi Ponds and Small Lakes, and SRAC 471, Fertilization of Fish Ponds. Practitioner discussion: Pond Boss forum threads Fertilization of ponds and Triple Super Phosphate.