Airmax KnockDown Defense 2-in-1 Liquid Algaecide & Herbicide for Rapid Pond Weed Control

Fast-Acting Knockdown Treatment Eliminates Algae & Weeds for Clear Water

Eliminates algae, duckweed, watermeal, hydrilla, and more
Restores ponds and lakes fast—see visible results within 3 to 5 days
Liquid formula makes measuring, mixing, and spraying fast and straightforward
2-in-1 formula acts as both an algaecide and an aquatic herbicide
Use 0.75–1.5 oz per 1/8 acre; ideal for ponds, lakes, and canals

Starting at $99.99

530268 16 Ounce is On Back Order Until 08/04/2026

530269 16 Ounce w/ Treatment Booster Plus is On Back Order Until 08/04/2026

Cannot Ship to AK, CA, CT, DC, HI, ME, NJ, NY, PR, RI, VT, WA, Canada → Click for Details

Airmax KnockDown Defense Algae & Aquatic Weed Control 16-Ounce Bottle. View Product Image

Airmax KnockDown Defense Algae & Aquatic Weed Control with Airmax Treatment Booster Plus View Product Image

Airmax KnockDown Defense Algae & Aquatic Weed Control label. Active Ingredient: Flumioxazin 42% View Product Image

A person wearing PPE pours KnockDown Defense into a tank sprayer. Text: Liquid Formation, Easy To Use View Product Image

How to Apply (Illustrated)- Step 1. Mix 1.5 oz KnockDown Defense per 1 gallon of water in a tank sprayer—step 2. Shake and mix contents—step 3. Apply mixture to target. View Product Image

A sunny, clean lake, with text: “Long Lasting Control; KnockDown works fast and provides longer lasting control than most contact products on the market”. View Product Image

Before & After image showing complete floating algae removal, with text: “Fast Acting 2-in-1 combo treatment”. View Product Image

Three close-ups of floating weeds and algae, with text: “Eliminates weeds & algae; floating algae, watermilfoil, watermeal, fanwort, duckweed, hydrilla & more!” View Product Image

Two ponds overrun with floating and submerged weeds, with text: “Surface or subsurface vegetation control”. View Product Image

Sunset reflecting off the ripples of a pristine pond, with text: “Reclaim the tranquility of a clean pond”. View Product Image

Eliminates algae, duckweed, watermeal, hydrilla, and more
Restores ponds and lakes fast—see visible results within 3 to 5 days
Liquid formula makes measuring, mixing, and spraying fast and straightforward
2-in-1 formula acts as both an algaecide and an aquatic herbicide
Use 0.75–1.5 oz per 1/8 acre; ideal for ponds, lakes, and canals

Starting at $99.99

530268 16 Ounce is On Back Order Until 08/04/2026

530269 16 Ounce w/ Treatment Booster Plus is On Back Order Until 08/04/2026

Cannot Ship to AK, CA, CT, DC, HI, ME, NJ, NY, PR, RI, VT, WA, Canada → Click for Details

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