In reading posts about water chemistry, many group members refer to measurements I don't have with my simple idiot litmus paper tester. I basically get 4 readings: free chlorine, alkalinity, ph and calcium hardness. Are these all that I need to test for? With a little trial and error my FC is 1-3ppm, Alk is 80ppm, PH is 7.5 and CH is 200-250 ppm. Is this optimal? If I need to test for other variables, what test kit is recommended? Thanks