We all have obsessed over our tanks. We research & find conflicting ideas. We hook up with "that guy" who has the tank we envy. We started with a 29 gallon. Making minor change actually were big change due to tank size.
When I first got into this hobby, I tested twice a day, always fiddling with something, had my hands in my tank, etc. Then I met a gentlemen in this hobby, that I respected. He gave me the one piece of advice I really needed. He told me to "slow down &quit messing with the tank". It was harsh & kinda peed me off. But he was right. I only test my water once a week (now I hardly test, the tank will tell you when it has a problem). I quit messing with the different pieces of equipment, and I hardly put my hands in tank (I have tendency to break corals).
I would also suggest taking your water to another LFS just as a comparison.
I use ELOS test kits for most of my tests. I use the Seachem kits to test Calcium & Magnesium (they have same I can test to verify the kit is good). I also use a Hanna Checker for Phosphaes & a refractor to measure salinity.
Like it's been said "Don't take what you read or are told as gospel." Take it slow. What may work for me or anyone else amy not work in yoru tank. If the tank is not showing any signs of stress then let it run itself.
FYI, what are your nitrates at & what are you basing "to high" on. Take a look at this link: Water Parameters
Dave-