Skip to content

Airmax Ultra PondWeed Defense Aquatic Herbicide


  • Broad-spectrum pondweed control
  • Fast-acting liquid formula
  • Best for submerged or floating weeds
  • Provides short-term control of duckweed in slow-moving water
  • Cannot be shipped to AK, AZ, CA, CT, DC, HI, ME, NJ, NY, PR, RI, VT, WA or Canada

Airmax Ultra PondWeed Defense works on pond weeds including submerged, floating and emergent weeds. This pond herbicide may also be used for short term control of duckweed in slow-moving water.

PondWeed Defense works best on actively growing plants. Early season emergent treatments may require additional applications. Use with Treatment Booster Plus for best results.

Weeds Treated

PondWeed Defense works on a range of submerged, floating and emergent weeds, including

  • American Pondweed
  • Bladderwort
  • Clasping Leaf Pondweed
  • Coontail
  • Curly Leaf Pondweed
  • Duckweed
  • Eurasian Watermilfoil
  • Hydrilla/Elodea
  • Lily Pads
  • Sago Pondweed
  • Southern Naiad
  • Watermeal
  • Water Shield

For specific treatment of cattails and other shoreline emergent weeds, try Shoreline Defense.

How to Apply

  1. Always follow all instructions on the Product Label and wear appropriate protective gear. Apply the product on a calm day during the weeds’ growing season.
  2. MixPondWeed Defense and water in a tank sprayer according to the label instructions.
  3. Add Treatment Booster Plus (if using) at a rate of 2 fluid ounces per gallon of treatment solution. Treatment Booster Plus enhances the effectiveness of PondWeed Defense by helping the product penetrate the waxy cuticle of emergent weeds. It also breaks through the surface tension of the water to treat submerged weeds.
  4. Thoroughly mix the solution.
  5. Adjust the pressure of your tank sprayer as needed. To minimize bounce-back, do not over-pressurize the sprayer.
  6. Spray the treatment directly on to visible weeds. To avoid fish suffocation, treat no more than half of the pond in a single application. (On hot days or in ponds with heavy growth, treat no more than 1/4 of the pond.)
  7. Most weeds die within 7 to 10 days of application. A second application may be needed in some situations.
  8. Once the plant is completely dead, use a rake to remove the dead foliage from the water. Failure to remove dead plant material could contribute to future weed and algae growth and add to pond muck.

Water Use Restrictions

  • Wait 3 days before using treated water for human drinking water.
  • Wait 1 day before using treated water for livestock and domestic animal consumption.
  • Wait 5 days before using treated water for irrigation.

View Product Label


1 Quart, 1 Gallon

You may also like…