Ph 7.2
Water hardness- 14.27ppm
*Result from water company
Good, you have very soft water, and that means with this type of tank you have more options.
There are a number of "nano" species that will mainly be wild caught and thus thrive in your water. Some of these have already been suggested. The brilliant red dwarf rasbora species in the genus
Boraras such as
Boraras brigittae,
Boraras maculatus. The orang-red Ember Tetra
Hyphessobrycon amandae. You could do a group of Trigonostigma hengeli, a tad larger fish but still suited to this sort of cube/column tank as they do not swim "lengths." One of the dwarf species of cory, like
Corydoras pygmaeus, or
C. habrosus. The
Nannostomus eques species of pencilfish for the surface. A grop of the dwarf pencilfish
Nannostomus marginatus. You could do a group of the false or green neon,
P. simulans. All of these are shoaling fish which means they must have a group, and I wouldnot go under 9 or 10 minimum for each species. Obviously not all of them, but you can see which you might like.