Submersed Weed Spot Treatment Recommendations Spot Treatment Pond Treatment Calculator Enter the surface area and percent coverage to get the amount of Hydrothol Granular treatment needed in pounds. Measure The amount of Hydrothol Granular treatment needed is pounds. Never Treat Over 25% Of The Pond At A TimeOptions:Hydrothol Granular 20 Pounds – $112.50 More Plant ID If Needed Pondweed Curlyleaf Pondweed Pondweed Submersed Plants