To some extent I will agree with Denny.
I was using sachem salinity salt for over a year and could never get my alk above 6. This affected my ability to keep sps, they never did well for me. Ive switched to reef crystals and have only done 1 test for mag, still at 1250, haven't tested for anything else as my corals look like they are doing better regardless.
When I first set up my 55, I tested all the parameters all the time. After 6 months I stopped as things were fine, corals growing, fish happy, tank is now 1 1/2 years old. The 180, tons of coral loss, lps, sps, but then others were doing great. Tank is only 6 months old, so I stopped messing with it and stopped adding corals. I can't keep up Witt the experienced reefers and have a full tank in months, that is my biggest challenge. Tank envy
I've switched to reef crystals and halfway through the bucket, things look better but not testing.
The argument over water changes, to do or not, there's points to both sides. I've increased the 180 weekly, the 55 has always been every 2 weeks. Not a strict schedule as summer kinda says there's funner stuff to do.
Shelley I'd say leave the tank alone, do what you can for water changes, but if the corals are happy, growing and good color, then whatever is in the tank is working.