Man, if it were me, I'd just let it be, don't stick hands in the tank, let your levels come down while keeping an eye on calcium levels since its at 420 and good, stop dosing nopox, and go get some vitamin c and dose about 1,000mg for a few days than up it to 1,500mg for another few days and again up to 2,000mg! This is what I did starting about a week ago and my ZOA's look brand spankin new and even popped out 1-3 heads! Keep an eye on your levels while coming down, stop dosing nopox, and dose vitamin c with your basic husbandry and water changes of course and I bet you $100 you'll come back next week posting good results! Cheers man and good luck!