This will help too: it's a no ammonia condition even still. Due to compounding mentioned earlier, you would be increasing daily until a total crash within quick time
That's not occurring you just have angry corals. There is no biological condition in which an aquarium oxidizes 90% of a given bioload and can't handle the last ten percent each day and holds there. Lack of bac is a quick kill for your tank, within a day. Never an extended event.
that polyp behavior comes about due to many issues, proceed either way you choose wchange/no water change as ammonia isn't the risk here.
Im going to reread first post see where these rocks came from, how long they were underwater in total here. The sand appears to be wet pack sand, checking to see if that brought in bac via the sand as well. Need to catch back up on this one.
The first post implies these are the rocks from the twenty gallon just moved into a bigger tank, with no increase in bioload. Changing out corals and cuc doesn't count as heavy loading. The bac moved over along with the rocks if I'm reading the first post correctly