Natural things to use to lower pH are usually things like driftwood, Catappa leaves, peat moss stuff like that. I would advise against pH up and down chemicals. Wild pH swings will kill your fish fast. Plus you don't want to have to mess with it at every water change to make sure its correct. Easy to make mistakes that way.
Mine sits at 8.2. Keeping it stable is more important than ideal. Unless you are looking at some super pH sensitive fish I would just leave it, and get some driftwood or something to lower it naturally.