water test

Fellows I'm in need of some assistance, I purchased a red sea kit and a salifer kit I tested alk with read sea first 3 days ago and it tested shy of 6.2 , mg and ca they did't even make it in to the charts (very low), so I starting dosing accordingly to rise up my parameters, today I retested using both salifert and red sea, after 3 consecutive tests, salifert was at 8.9 , and and red sea 6.2 then dropped to 5.6, sps corals are not happy,
So if red sea test kit is accurate numbers should have gone up since I started dosing correct, WT , don't know what to do here should I dose or not.
Thanks