I checked the tank water and it's fine, My Congo Leaf is fine..my catfish and ABK ...fine. I found him dead on the bottom...at first i thought he was hanging out...but i didn't see his gills moving..so i touched him with the net...he was dead.
I did add sechems purigen in a mesh net to my HOB filter...it has cleared up my tank of driftwood tannis...but with or without tannis, again..my other fish are fine.