Purely out of curiosity, what salt are you currently using?It's very frustrating as I've poured a lot of time and money into the tank and considering ive tried my damnedest to do everything right the winds kind of gone out of the sails. I feel like any move i make from here will just be blind grasping in the dark that'll simply be a waste of more time and money.
I might switch salts to see if that's a source of contaminant and maybe the new salt will possibly bump up the minor and trace elements. But other that I think I might just stick to weekly waterchanges and let time decide. Either the tank turns a corner and improves or it doesnt.
As for the first paragraph, sometimes thats all we can do, wait and see.