According to the manufacturer, there is no wait time for swimming after applying Cutrine Plus Granular Algaecide.
Yes, livestock such as cows, sheep, goats, etc can drink from water that has been treated with Cutrine Plus Granular Algaecide. Directly from the label: CUTRINE-PLUS GRANULAR ALGAECIDE may be used for swimming, fishing, drinking water treatment, livestock watering or irrigating turf, ornamental plants or crops following treatment.
The Cutrine Plus Granular Algaecide should not be dissolved for a spray solution. Cutrine-Plus Algaecide can be mixed with water and applied in a sprayer for the application you are seeking.
Cutrine Plus Granular Algaecide is not labeled for use inside of drinking wells. According to the manufacturer, if the product is used in a pond/lake/stream, exactly as the label states, the water out of the pond can be safely consumed. However, this product is not labeled for use inside of wells.
The Cutrine Plus Granular Algaecide is not labeled specifically to treat string algae so we cannot say if it would be effective on treatments for it or not. We do carry a product called Crystal Blue Copper Sulfate which is labeled for string algae control. We also found this article online that goes over the best methods for eliminating and preventing string algae in your pond in the future: Controlling String Algae
You may use the Cutrine Plus Granular Algaecide in your pond as long as you are following the instructions on the product label. The label does not state that there are any restrictions on applications made to moving water.
Cutrine Plus Granular Algaecide is not labeled to control grasses or other weeds or for terrestrial use. We recommend getting the grassy weed you have growing at the edge of the pond identified to find out if Cutrine Plus would be an option, or if you're in need of an aquatic herbicide. AquaPlant is an excellent online guide for assistance with identifying and treating aquatic weeds and algaes.