This is a non-electric water proportional dosing device that is installed directly into the water supply line of the livestock house.The device operates by using the flow of water as its power source. As the water flows through the device it activates an internal motor piston, which in turn draws up concentrate from a stock solution container via a dosing piston. This concentrate is then injected and mixed within the dosing unit before the water pressure forces the mixture out downstream towards the animal housing. The dose is directly proportional to the volume of water entering the device, regardless of variations in pressure or flow. The D25F2 has a fixed dosing unit. For every 100 litres consumed 2 litres of concentrate is mixed in 98 litres of water.