Ok i have never ever tested my water in my tanks, And i have never had a problem, What should i test my tanks for? I dont got the $$ to buy a whole test kit, And i know not to get the strips.. what would you buy if you were me?
IMO I think once a tank is set-up and running well, pH and nitrate would be the most important. The AP master test kit is really good though and not that expensive.