If it is any consolation, I picked up 1 from TUIC several months ago. Despite eating, growing, and looking generally very good, it succumbed to what I assume is elevated nitrogenous wastes. Not ammonia or nitrite, as neither of these were at detectable levels. Nitrate was only 30 ppm. Evidently, these pikes need colossal water changes as any increase in metabolic byproducts does them in. Mine was getting 50% water changes twice a week, but evidently the fishes metabolism and digestion outstripped my schedule.
I've only run across a few fish - ever - that took that kind of attention. IMO, these fish were more trouble than WC discus!
That really sucks about losing 2. Do try them again. The bright side: more room. Any idea of the exact water conditions these Crenicichla are collected in?
J