I would do a 100% water change to reduce everything to 0 then redose ammonia as per the link in post 5 above and see whether you have any action going on in there.
Several water changes since last post. Crystal clear and reading 0,0,10ish on amonia, nitrite, and nitrates respectively. Adding 15-20ml of ammonia in morning and next morning still reeading 0. Gonna add 2 Syndontis cats next week...