I've been waiting to get a BTA myself.
From what I have read on the Anemone forums you're gonna want to have good lighting, low to no NO3 and PO4, decent water movement and stable temps and salinity.
I'm curious how you have 0 on the Mg, Kh, and Ca. Do just use standard salt mix for water changes? If the trace elements are required for nems then could probably just switch to reef salts for water changes to bring up the levels.