not sure on calcium as i dont have a tester yet but i dose the 55g with reef calcium 2 times a week + iodine and calcium suppliments every day with a different chemical
It seems to me you are over dosing
Especially calcium (which you state you have no test kit for)
You definitely need a calcium test kit!
You need to stop dosing your tank as much as you are doing, and let things settle down naturally, how long has your tank been running!
Try & take it easy & not panic ( I like you did at first)
Hope this helps