Hi in my goldfish tank I have a lot of hard water spots that are really annoying. All of them lie on the back of the aquarium and were caused by water splashing from my bubbler onto the back. If there any way to get rid of these? I can just fit my finger behind the tank because it's pressed on a wall. Is it safe to put my fish into a 10 gallon for a day and do a 100 percent water change and give the tank a good vinegar scrub? I have a canister filter with developed media and no substrate. Thanks for any help!