I can honestly say I do not test anymore. The only test kits I own are my corals, they tell me when somethings wrong. If nothing looks happy, I do a waterchange, if nothing changes within 24-48 hours, I will take my water to the LFS where they'll do Ca, Ph, trates, trites, amm, and alk. I haven't had to do that yet tho, since I haven't had any problems in about a year.