Terry from Gadsden writes
Is this product save to use in ponds that have fish in but you want to kill water lillies
Diquat Water Weed and Landscape Herbicide is safe for ponds with fish when used as directed on the product label. Per the product label: "Treatment of dense weed areas may result in oxygen loss from decomposition of dead weeds. This loss of oxygen may cause fish suffocation. Therefore, treat only 1/3 to 1/2 of the water body area at one time and wait 14 days between treatments." We do not carry an algaecide or any other products that are safe to be used in specifically koi ponds at this time.
Answer last updated on: 04/02/2020
