I'm thinking some wisteria in the middle with some other plants. Not sure at the moment. As to the fish, since it's my gf's anything pretty would work.
This is a good plan for the present, good thinking. Monitor fish behaviours, etc. If nothing shows up, well and good. I hope so.
get a big fresh water tank and a big planter with your favourite veggies and use the weekly water changes to water the veggies. I like to water my plants
I would not add any betta in with these small fish. The possible trouble works both ways.
Soft water opens up lots of options with the pencilfish,
Did a 80% water change. Also added some charcoal to the filter to remove any excess meds that might have remained after water change.