before adding danios you should make you
WCMM happy by getting some more.
WCMM's are, like danios, schooling fish and
need to be in groups of no less than 5.
then and only then would I consider adding danios,
depending on the amount of filtration you have.
if you have a good external filter then you
could add 5 or 6 danios, but I'd steer away from
ZD or LD. dwarf danios or glowlight danios are
slightly smaller than ZD and they do not nip fins.
If you only have am internal filter, I feel that you
would be at you stocking limit after adding the WCMM's