Hydrothol 191™

Hydrothol 191

Hydrothol 191™ is a registered, broad spectrum, organic, aquatic algaecide and herbicide. It is an excellent alternative to copper products. Hydrothol 191™ is effective on controlling hydrilla, milfoil, pond-weeds, elodea, chara, spirogyra, and pithophora.

  • Does not bioaccumulate in the soils
  • Effective in murky water
  • Application should not exceed 0.45 gallons per acre-foot of water
  • Can be harmful to fish populations, if used incorrectly
  • Apply early in the spring, prior to fish spawning

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2.5 gallons $284.99


Shipping via UPS or FedEx is prohibited. Pick up or shipping via motor freight are both purchase options.  When ordering, you will be contacted within 1 business day with a shipping quote.


Due to governmental regulations, we do not ship these products to the following states: CA, CT, ME, NY, NJ, OR, and WA.  Read and follow all local, state and federal regulations pertaining to the use and application of these products before ordering.  We do not recommend the application of any chemical for algae, weed, parasite, or disease treatment during the summer months in ponds without an aerator in operation. The reactions of many chemicals cause rapid decomposition of heavy vegetation growth and/or greatly reduce the oxygen content of the water, causing distress and possible death to the fish.