I'll just pick up on a few things from this thread.
I agree, get rid of the Chinese Algae Eaters. Even if they did turn out to be the Siamese Algae Eater, they still get much too large for a 10g and a group is best. You can read about these fish in our profiles as Barb suggested, click the shaded names to see the fish's profile.
Second issue, the ammonia/nitrite/nitrate...if ammonia or nitrite is above zero, do a partial water change of 50% of the tank using a good conditioner. With a new tank and these issues, Prime or Ultimate water conditioners are good. They handle ammonia and nitrites as well as chlorine/chloramine.
The pH is low, but this is good and bad depending. We still need to know the pH of the tap water on its own to assess what is occurring. If the tap water is also acidic, that is fine but you will not have success with livebearers. Guppy and Molly need harder water or they will develop various health problems and die prematurely. Tetra, kuhli loaches, and many other fish are soft water and will be fine in a lower pH. But it can get too low, that's why we need to know the tap water pH to assess things.