The risk of oxygen depletion becomes greater during the hot days of summer. Biological control usually refers to triploid grass carp. Grass carp, when stocked at the proper density, primarily aid in the control of the submerged plants or mosses. By state law, grass carp must be permitted through Texas Parks and Wildlife before being purchased. They may only be purchased from a fish farm holding an Exotic Species Permit.
Mechanical control involves the use of weed harvesters, seines or even removal by hand.
This technique is usually of limited value in typical farm ponds.