Poly line size when dispensing TC & FB through Trifoam gun

[1carwash1]

If the TC & PS are moved so that they dispense from the triple foam gun is it really necessary to use 3/8 poly for the liquids? Currently, I dispense PS & TC from the high-pressure gun and both are fed to the high-pressure boom with 1/4 poly. Is 3/8 really needed?

 

[MEP001]

I would use 3/8" ID for presoak, but 1/4" is enough for tire cleaner and the air.