Please need help on hard water line residue
Hello everyone, i recently tried cleaning my aquarium, and since i haven't done anything to it for a while the water started evaporating and left some nasty "hard water residue" on the top level of my aquarium. i tried everything from scrubbing to using a mix of water and vinegar and i thought it was gone so i filled up the tank once again. Now i find out it's still there and worst of all, my aquarium is cycled and with fishes.
Is there anything i could do?