If you found carolina water-shield in your pond and want to get rid of it, the best option is to use mechanical methods of removal, like raking, seining, cutting, pulling, etc., in combination with phytoplanktons. Mechanical removal will need to be repeated a number of times during summer, because the plant will regrow from the remaining roots and seeds. Carolina water-shield can be controlled by exhausting the remaining plants with regular raking, and by introducing or stimulating the growth of phytoplanktons that help to prevent the development and further establishment of this type of weed. The use of herbicides in aquatic environments is not advised, because it is impossible to avoid affecting non-target species.