Hi K, to get your 7ppm down closer to 4ppm, just siphon off a few gallons of water, replace it with tap (and a little conditioner as usual) and see if you've made it to something that looks closer to 3 to 5ppm, any of which is fine for this early stage.
I would not think of having to do a water change in a negative light, its often part of normal happy rhythms of fishkeeping. It has only positive effects usually on growing bacteria, since it gives them some fresh oxygen, fresh trace calcium and magnesium and other odd stuff they use in their cells and then thanks to you they also get some fresh food in the form of ammonia, lol.
The discussion about the anti-mold, remember, is just speculation and not very knowledgeable speculation at that! Is the background the the now dry sealant still in there (I forget?) Maybe you've got the tube still and could communitcate with the manufacturer and find out what actual antibiotic or drug they use and post it here. We do sometimes have members who know about some of these. Meanwhile, I would guess that you have just as much chance that this is not a factor at all as you have that it is!
Remember, all this stuff is like building houses or raising kids, the more fuss and pain, the bigger the reward eventually! But we can promise it won't be on that scale.
~~waterdrop~~
