Technical screenwash pipe leak

[850kd]

Appears to be leak from pipe as it leaves reservoir tank . Anyone else experienced this ? Any ideas as to internal diameter of pipe?
This is not easy to see and even harder to fit because when the car is on the road/level it is not visible without using a mirror .
I will need the car on a lift to fix but want to have the right size pipe ready to fit when we do !

 

[yam]

You can use just garden 1/4'' Hose, it cost almost nothing.....