Hi Robert, can't imagine that pH of 6.3 is to low. Try raising pH by aerating if possible or add lime stones or oyster shells. HTH Don't use baking powder (unless you know its pure sodium bi carbonate) because some baking powders contain ammonia !! Wild caught apistos may carry a lot of infects like nematodes which aren't visible. Another problem is they may have been without food for a very long time so they may be weak - it may need a while until they eat normally. Good luck Thomas