I'm using the Exact iDip tester. Run Alk, Calcium, Hardness (which then gives me my Mg level), Nitrate and Phosphates weekly. I have a Hanna Alk tester to run random Alk and to double check my iDip tester. It's been extremely easy to use this kit and my iPhone records my results via Bluetooth and archives
Use the Exact iDip test kit. Weekly Alk, Calcium, Hardness (which generates my Mg), nitrate and Phosphate. Easy to use and it archives via Bluetooth to my iPhone. No colors to match, all results are digital. Have a Hanna Checker for Alk to double check if in doubt. Send ICP's every few months
Salifert alk every few days. Hydrometer for SG every few weeks. Laser Temp Gun for temp every few weeks. Calcium maybe every 60-90 days - I have a lot of clams and they do not use carbonate and calcium completely in balance. Nothing else, even though I have a bunch of others.
I have a Hannah Ultra Low for phosphate, but I do not really use it except on the frag tanks with no/few fish... my display always stays very low on it's own.