Ditch the test strip, very inaccurate. I use red sea and salifert for calcium and alk. Hanna for phosphate. Where you live, so someone can point you to a reliable lfs?
RC has a new formula with low alk for years now. They just never mention it. Think alk is around 7-8 now. Water change is to bring up the salinity and then test to see what he needs to correct by dosing the right amount.
Well, it all depends on what you keeping in your tank. Also what type of lights you switch out previously and par. I always start low then acclimate the corals to the new lights.
So, have you ever come home and glance at your tank to make sure everyone is happy and notice something is kinda weird looking to your favorite coral? Think we all have but still a moment of " Oh hell no this is happening". Then look closely to find that your going to have more than one now lol...
Reef crystals is actually higher in ca and mag. I personally like to run my salinity at 1.025 to 1.026. Also raising that will bring up your parameters a little. Remember to raise everything slowly. Biggest mistake someone can make when they see their corals is unhappy is changing things too fast.