HarpoonGranular

According to the label From the product label

Harpoon Granular is a chelated copper herbicide designed to control various submerged aquatic plants. Its active ingredient is Copper Ethylenediamine Complex, containing 3.41% elemental copper. It is effective against species such as Hydrilla, Egeria (Brazilian Elodea), Najas, Ceratophyllum demersum, Elodea canadensis, Myriophyllum spicatum, Potamogeton pectinatus, and Potamogeton nodosus. The product is intended for use in quiescent or slow-moving bodies of water, including lakes, ponds, reservoirs, and golf course water features. Application rates vary based on the target plant species and their growth height, typically measured in pounds of product per acre-foot of plant height. Users must be cautious of environmental risks; copper is toxic to fish and aquatic organisms. To minimize oxygen depletion caused by decomposing plant matter, do not treat more than half of a water body at one time and allow at least 14 days between treatments. When handling, wear long-sleeved shirts, long pants or coveralls, shoes and socks, chemical-resistant gloves, and goggles or a face shield. This product is corrosive and can cause irreversible eye damage; if contact occurs, rinse eyes for 15-20 minutes. Always follow specific site restrictions regarding water hardness and pH levels to ensure efficacy and safety.

Application rates & sites 1

Timing & weather

• Apply early in the day under calm, sunny conditions.
• Best when water temperatures are at least 60°F.

Use restrictions 7

• Do not treat more than 1/2 of the water body at one time.
• Do not apply more than 320 lbs of product per acre-foot plant height per year.
• Do not apply more than 21.7 lbs of active ingredient per acre-foot per year.
• Do not make applications less than 14 days apart.
• Do not use in small volume garden ponds.
• Avoid treating waters with pH <6.5, DOC levels >3.0, and alkalinity <50 ppm.
• Do not apply in a way that will contact adults, children, or pets.