Yeah, that might be a bit of a false positive. I would think if you still had a significant ammonia level, you would also see some nitrites. Some test kits can be off, and the colors can be misleading. I used to give myself headaches trying to read the ph tests. Is that purple-green, blue-green, or blue-purple..???
So I got an electronic tester for ph, no more headaches. I wish they had one for all tests...:happyfish