Hydrothol 191 Granular Algaecide/Herbicide is a selective, rapid-acting, contact herbicide and algaecide. Controls submersed weeds and algae in lakes, ponds, irrigation canals, and drainage ditches. Works rapidly enough to be effective in both still and slow-moving water. 

• EPA approved
• Works quickly
• Not swimming or fishing restrictions
• Works on both Algae and Pondweeds!

Available in a 20-pound bag only. 

*Cannot be shipped to: AK, CA, CT, DC, DE, HI, MA, ME, NJ, NY, PR, RI, VT, WA 

Application Rate

Direction for use:

To apply Hydrothol 191 Granular, simply broadcast the granules uniformly over the water surface above the target plant, by hand or with the use of a mechanical spreader.

              
Pro Tip:

Heavy algae or pondweed infestations should be treated in sections 5 to 7 days apart to avoid oxygen depletion from decomposing dead vegetation.

Water treated with Hydrothol 191 Granular should not be used for irrigation or human and animal consumption for 7 to 25 days depending on the application rate.

Please see label for complete product information. 

Can not be shipped to PR, HI, AK, or Canada

 Product SDS Sheet & Label

Hydrothol 191 Granular SDS Sheet                    Hydrothol 191 Granular Label