Many states have regulations on weed control products, but they are frequently unable to enforce them. We have customers in every state.
Aquatic Vegetation Control Laws and Permits Info: https://www.in.gov/dnr/fishwild/files/fw-Aquatic_Vegetation_Control_Laws.pdf
For most people the rule is: A landowner or tenant adjacent to public waters or boundary waters of the state, who chemically, mechanically, or physically controls aquatic vegetation in the immediate vicinity of a boat landing or bathing beach on or adjacent to the real property of the landowner or tenant if the following conditions exist:
The area where vegetation is to be controlled does not exceed:
(i) twenty-five (25) feet along the legally established, average, or normal shoreline;
(ii) a water depth of six (6) feet; and
(iii) a total surface area of six hundred twenty-five (625) square feet.
If your total area is greater than what is listed above, you will need a permit.
Permit: https://forms.in.gov/Download.aspx?id=9448
Be sure to ask your local DNR, US Army Corps of Engineers, Department of Fish and Wildlife, town, etc. for any permit information.