Hydrothol 191 Granular 40 lb & 20 lbs Herbicide

Hydrothol 191 Granular is our #1 selling chemical for killing submersed aquatic weeds. It is extremely effective against a broad spectrum of submersed weeds and it also controls problem algae at the same time! 

Hydrothol 191 treatment rate example: *Typical Rates: 7.5 to 12.5 Lbs per 1000 sq ft. 4 Ft average depth.

Recommend first treatment May/June and second treatment July/August.

Apply with a hand scoop or hand held spreader.

*Consult Label for exact doses, additional restrictions & important application directions. Rates vary depending upon depth and plant types. Dose requirements are less for whole waterbody treatments like a pond.

Download Relevant Product PDF's below:

Product Label

Safety Data Sheet

Water Use Restrictions: None on swimming, none on fishing, *none on established turf.
Container Size: 20 Lb. resealable bag(s)
Formulation: Granular

We cannot ship this item outside of the Contintental United States.

What kind of aquatic vegetation will Hydrothol 191 Granular work on?

HYDRILLA - Excellent
EURASIAN MILFOIL - Excellent
BUSHY POND WEED - Excellent
CLASPING-LEAF POND WEED - Excellent
CURLY-LEAF POND WEED - Excellent
FLOATING-LEAF POND WEED - Excellent
HORNED PONDWEED - Excellent
LARGE-LEAF PONDWEED - Excellent
LEAFY PONDWEED - Excellent
SAGO PONDWEED - Excellent

CHARA - Good
COONTAIL - Good
ELODEA - Good
FILAMENTOUS ALGAE - Good
PARROT FEATHER - Good
PLANKTONIC ALGAE - Good

AMERICAN LOTUS - Fair
SPATTERDOCK - Fair
WATER PRIMROSE - Fair
WATER SHIELD - Fair

Remember to check out all of our other products for sale designed to kill, cut & get rid of lake weeds. 

• Treats 4,000 - 16,000 ft²
• Works best on firm, sandy lake man
• Improves access to water for recreation
• No restrictions swimming or fishing

Hydrothol 191 Granular: Hydrothol® Granular uses 11.2% concentrated Mono (N, N-dimethylalkylamine) Salt of Endothall, and continues to be a highly effective herbicide/algaecide solution for a variety of aquatic nuisances. Be sure to apply this product when weeds and algae are actively growing. Susceptibility of algae may vary due to subspecies, strains or environmental conditions. There is also a liquid option but this is sold to commercial applicators only. Check permitting requirements in your area prior to applying.

EFFECTIVE HERBICIDE AND ALGAECIDE: Hydrothol ® Aquatic Herbicide and Algaecide has been successfully used for over 30 years. Today Hydrothol ® is used primarily as an algaecide. Hydrothol ® is the only registered broad spectrum organic aquatic algaecide available today. Hydrothol ® can be used in combination, in rotation or as an alternative to copper for control of algae.

ENVIRONMENTALLY SOUND: Hydrothol ® quickly dissipates in the environment. When properly used, Hydrothol® provides excellent algae and weed control, but does not adversely impact the fishery or the aquatic environment. Hydrothol ® does not bio accumulate in either fish or the hydro soil, and has a short half-life of less than seven days.

VERSATILE: Due to the fast activity of Hydrothol ®, it can be effectively used in slow moving water, such as drainage and irrigation canals. In addition, spot or marginal treatments are highly effective against noxious weeds and algae in lakes and ponds. Hydrothol ® is effective in muddy or murky water because it does not bind to the suspended sediment or organic matter.

HYDROTHOL: Hyrdothol ® provides control where you need it, in the application area, not away from the target area. For this reason, Hydrothol ® is a valuable tool in improving access to the water for recreational activities such as swimming, fishing and water skiing.

APPLICATION: Hydrothol ® must be properly used to avoid toxicity to fish. Only marginal or sectional treatments are recommended and should be only be made by qualified commercial applicators. Applications should be made outward from the shoreline or in strips to prevent trapping fish in the treated zone. Refer to label for proper application rates. Kill lakeweeds.

EFFECTS OF ALGAE: Algae can be detrimental to water quality. In fact, it may cause illness to swimmers and other water users. Poor water quality as a result of certain strains of algae may even prevent water-contact recreational uses including swimming, water skiing and use of personal water craft. Algae blooms are the leading cause of fish kills in the U.S., compromising fishery management programs.

Shipping Restrictions! This Product Cannot be Shipped to: Alaska or Canada

Feel free to contact us about other Lake shore & weed management products and services we provide!

763-551-1441

Transform your leaf blower into a handheld spreader 

Fits any blower with a 2-3/4 in. to 3 in. round style tube. Holds 4.25qt of material (Up to 7-9 Lbs of product) 1.25 inch gate valve for larger products Made in the USA