Outdoor ponds are difficult to manage and large amounts of algae and grass are a common infestation. The problem grows as a result of sunlight and slow water circulation. Grass carp are often used to manage the algae and grass. The carp suck the plant matter through their mouth and filter it for nutrients. The process significantly reduces the amount of plant matter in the pond. Grass carp are also desirable because they are not violent and coexist with other fish species.
Observe your pond to determine the need for carp. Algae blooms that blanket the entire pond require a high number of carp per acre and minor vegetation problems require a small number of carp per acre. Stock 20-30 carp per acre for minor vegetation problems and 200-250 per acre for major vegetation problems. Choose a relative number of fish depending on the extent of the problem.
Check your state's laws and apply for a stocking permit if necessary. Locate a hatchery with a triploid grass carp population for sale. Triploid refers to chromosome viability. The triploid population is sterile and cannot reproduce. The triploids are required by many states with concerns about invasive species.
Purchase the carp and arrange for a delivery date. Consult with the hatchery about a date that is low stress for the fish. Spring and fall have moderate temperatures and are typically the best low-stress option.
Plan a stocking method to ensure the fish safely reach the pond. Ponds with road access are ideal as the fish are unloaded from the stocking truck through a tube. Prepare buckets for transportation to walking access ponds. Minimise the amount of time the fish spend away from water and minimise contact with the fish to reduce stress and prevent death.
Stock the fish in the pond. Submerge the bucket in the pond water for one minute to allow a gradual adjustment to the temperature. Empty the fish directly from the hose on a stocking truck and hold fish upright if they are in shock and will not swim.
Monitor the pond for several weeks after the stocking. Look for dead fish that did not acclimate to the new environment and remove them from the water.
Consult with a biologist if you are unsure about stocking fish. There may be a cheaper and easier solution to your vegetation problem and a biology consultant will save you money in the long run.