- Many types of fish like to eat or uproot submerged plants. Koi, silver dollars and rainbow fish are three that can be particularly destructive to many — if not most — aquatic plants. However, they are not the only ones. Cichlids, tetras, plecos, mollies, pacus and tropheus are all listed as herbivores, meaning they like to eat plants. Even some species not generally thought of as herbaceous can strip a tank bare of vegetation if they are not properly fed — goldfish and angelfish belong to this group. Regardless of what you may have read or may be told, most species of aquarium and pond fish can and will eat plants or dig them up for sport if not properly fed or kept happy.
- Surround your plants with submerged plant protectors made from nylon netting. These protectors can be purchased or homemade. For bottom-rooted plants, purchase a protector with an open ring at one end and a drawstring at the top end. Set the open ring end over the plant, allowing the plant to grow inside the mesh protection. For floating plants, insert them inside a nylon bag with a drawstring at one end, and allow the bag and the plant to float freely in the pond or tank. The nylon allows for the free flow of water to the plant but protects the plant from fish.
- Use large rocks or other weights to weigh down the ring at the bottom of rooted-plant protectors to prevent large fish or turtles from lifting the protector off your plant. Most commercial plant protectors have open rings that are either 1 foot or 2 feet in diameter.
- If leaves can fall into the pond from outside, or if not all of your plants are protected by underwater plant protectors, then it may be wise to cover your filter — especially the intake nozzle — with nylon mesh to prevent leaves or entire plants from being sucked into the filter intake and potentially plugging it, which could cause the filter to overheat.