Originally Posted by outpost
The pH of my tap water is 8. My local fish store carries a large variety fish including neon tetras and discus.
Knowing this, some plant suggestions would be:
Vallisneria (this does exceptionally well in harder water)
Sagittaria (very similar to Vall in appearance)
Echinodorus bleherae (the most common "sword" usually available, and one that does well in harder water than many others)
Echinodorus tenellus (the pygmy chain sword)
The above are substrate-rooted plants; all send out runners except for E. bleherae that has a flower spikes on which daughter plants will develop underwater, so these will reproduce once settled. There are also stem plants, most of the commonly available ones manage in harder water fine.
As for fish, livebearers and rift lake cichlids are ideally suited, and some of the characins (tetras) will manage OK [check out the Fish Profiles section, this is mentioned in the water parameters for all species]. As you are talking about a 10g tank, rift lake cichlids are not an option. Livebearers need a bit of room, although there are some interesting small species (not just guppies, some much more interesting). Shrimp would do well too, and provide some bottom interest, although a trio of Corydoras aeneus or C. paleatus (both adapt to harder water fairly well) are possibilities; the dwarf species which would suit a 10g do not adapt to hard water.
Hope this is of some help. Sometimes it takes quite a bit of searching to find some of the "rarer" fish, but the wait is worth it when you end up with really suitable fish in your aquarium rather than filling it with whatever is available. Only this week I added some fish to one of my Amazonian setups that I have been waiting for several years to find.