I am fine with testing high range pH, ammonia, nitrite and nitrate. But getting into things like calcium, magnessium, alkalinity, I am not so good at. I have tried API (for calcium) and Red Sea for CA, Mg, Alk. Any suggestions for easier tests for those last three? I have heard good things about Salifert and I am going to try and purchase them soon.
My other issue/concern is keeping things stable. My ammonia has been either zero or relatively close to 0 (I don't 100% believe my API test kit, but my Seachem monitor says 0, and LFS says 0). My Nitrates are between 10-20ppm. I have issues also keeping my salinity stable, it is usually all over the chart in the "okay/safe" area. This has been due to skimmer issues for the most part, and making sure water change water is at the right level.
And for referance, I have a 90g tank with an ~20g sump with a small refugium, 10g ATO. Tank was set up in September, plan on doing a FOWLR and Inverts tank (currently only 2 clown fish, shrimp, urchin, crabs, snails). All fish and inverts are thriving, I even have feather dusters growing and doing well. I do plan to have a clam(or more than one) and an anemone, so stable water conditions are a must. I currently use Instant ocean salt, 15-20% water changes every other week (just did one yesterday) with RODI water (TDS= 0).