Originally Posted by TheCat
Well I've just tested the water and I have
I'm worried about the hardness of the water. I don't know anything about which tropicals would be able to live in this
Those are interesting numbers, as they relate to each other, and not a problem. The GH at 180ppm is roughly 10 dGH, so in the lower medium-hard range. The pH is slightly acidic. With these, I would suggest what we term soft water forest fish such as many of the characins, cyprinids, anabantids, non-African cichlids, catfish. The GH is not too high for most of these, except some of the rarer wild-caught, but it could be diluted a bit with pure water. The pH would likely lower slightly, also good.
If you did want to go in the opposite direction, say with livebearers, I would raise the pH above 7, close to 8. This could be easily done with some crushed coral gravel in the filter, a couple tablespoons. The GH at 10 is fine, but the acidic pH qwould be detrimental. That's only if you wanted livebearers.
If you check our profiles, second tab from the left in the blue bar across the top of the page, you will find that each contains the preferred water parameters for the species, along with minimum tank sizes, numbers of each species where necessary, compatibility, etc. If you come up with some species and want any clarification, just ask.