Can you help me with this project? Fluid injection

Ok I have received a project from my engineering class at

school and need some help.

Here it is: Please excuse the elementary task!!

Problem: I have to combine 2 liquids by using an injection type method.

The main component is H20 the other to be injected into the line of H20 is Syrup "Viscosity similar to H20".

I have to achieve a constant "set" flow rate of the syrup into the main line of water 

when the water is flowing. 

Solution:  "My Idea" I will be putting together a PVC pipe with water flowing through it

attached to the pipe will be a tap with a connector to my syrup bottle. As the water flows a certain amount of syrup will be sucked into the water and blended. 

The problem I have is regulating the amount of syrup. I was thinking some kind of Jet? Venturi...

Thanks in advance