Roundup Custom 2.5 Gallons (53.8% Aquatic Glyphosate)Roundup Custom – 2.5 Gallons (53.8% Aquatic Glyphosate). Application and use flexibility for weed and brush control by land or water. Offers the flexibility to choose the right surfactant, tank mix or custom herbicide blend for the job at hand. Non-selective and highly effective on more than 190.