Duplicareus are fine in hard water. I have a group and they're doing great. Granted they haven't spawned yet but by all accounts they spawn ok in hard water, it's adolfoi whose eggs struggle to develop without soft water. I think most cories do well in whatever water you give them provided there are not extremes. You just may have some issues raising the spawn of species like adolfoi.Hi Mort,
I assume your tap is already fairly soft? Or is it hard like mine? I do like Corydoras Duplicareus which is similar in size to the Panda, but, as Darrel mentioned that would require soft water as it comes for the upper Rio Negro.
How did you source your Panda and Adolfoi?