Testing Nute levels without an EC tester

Hi all. Just wondering if there is a way of measuring how much nute I should be adding to my water without an EC tester?
I have plans of getting on but money is real tight at the moment so forking out the coin for one is not doable in the near future.

Spose I should say I am using CANNA VEG A & B solution. My tap water PH is 7 and according to a friend who grows in the area the standard water is pretty good.