Fluid injection system for dispensing a solution into a fluid flow in a flow line, the fluid injection system including a storage tank having product to be dispensed therein; an inlet connection diverting fluid from the flow line into the tank; an outlet connection returning a mixture of fluid/product back into the flow line; a metering gauge in fluid communication with the inlet connection measuring water flowing into the tank; and a metering head connected to the storage tank and having multiple ports for connection to the inlet connection depending on whether the product to be dispensed is in liquid dry form. The inlet connection includes an inlet probe having an opening defined by an arc at a downstream side. The outlet connection includes an outlet probe having an opening having an angled cut facing downstream, such that a pressure differential is created between the inlet and outlet probes.
