Pond Management - South Carolina Department of Natural Resources

Herbicides
Aquatic herbicides are a widely used method of vegetation control
in ponds. Properly applied, they can safely and efficiently combat
a number of nuisance plant species. Accurate identification of
the target plant is an absolute must prior to treatment as many
herbicides are very selective in their action and level of control
on a particular weed species. Always obtain professional advice
on the plant’s identification and recommendations for the
appropriate herbicide treatment. This assistance is available,
free of charge, from several state and federal agencies including
the regional offices of the SCDNR. It is neither economical nor
environmentally responsible to use a herbicide that is not effective.
Use only herbicides that are federally-approved and labeled for
aquatic weed control. Always Read the Entire Label
Before You Use Any Herbicide and Follow Label
Directions Carefully. Misuse or the use of unapproved
herbicides could be dangerous to fish, mammals, turtles, birds,
bankside vegetation, etc. They could cause downstream damage
for which you could be held liable. If you have any doubt about the
meaning of the label directions, contact an expert – don’t guess.
Biological Control
Several species of fish have been successfully used to control
weeds in recreational fishing ponds. These include tilapia (African
bream) and triploid grass carp (white amur). Be aware that other
species of fishes may also consume vegetation, but for the most
part have been shown to be marginally effective or may be illegal
to import or possess in this state. If you have any doubts about a
particular species of fish, contact the SCDNR for clarification prior
to obtaining them. Tilapia are tropical fish that are advertised by
their producers to consume a wide variety of aquatic vegetation.
Unfortunately, they are usually less effective than advertised,
but will control some species of filamentous algae when stocked
in the spring at rates from 250-400 fish per acre. Winter water
temperatures are fatal to these fish so annual restocking is required.
Triploid grass carp are a sterile form of the original white amur.
They often produce better long-term results for the money than
herbicide treatments. Although grass carp will control a wide
variety of submersed vegetation, they should not be considered a
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