So Sundays are my tank cleaning days. I do my weekly cleaning/maintenance and tests. I test my Nitrates and Phosphates before my WC but my Mag, Alk, and Calcium after the water change. Alk I also check on Wednesdays as it tends to swing more in my newer tank so I like to ensure my dosing is on point. Obviously the nutrients NEED to be checked before the water change but I'm wondering if I should also be checking the other parameters before it. I use the results after the WC to make any corrections (Instant Ocean Reef Crystals tend to be lower in Mag than I like) that I need which usually isn't much. Just wondering what everyone else does. I don't wanna have to test twice (before and after) if I don't need to.