When I try to parse some html that has sprinkled through it and then echo it, the "turns into" this character: Â. Also, html_entity_decode() and str_replace() doesn't change it.
Why is this happening? How can I remove the Â's?
The non-breaking space exist in UTF-8 of two bytes: 0xC2 and 0xA0.
When those bytes are represented in ISO-8859-1 (a single-byte encoding) instead of UTF-8 (a multi-byte encoding) then those bytes becomes respectively the characters  and another non-breaking space .
Apparently you're parsing the HTML using UTF-8 and echoing the results using ISO-8859-1. To fix this problem, you need to either parse HTML using ISO-8859-1 or echo the results using UTF-8. I'd recommend to use UTF-8 all the way. Go through the PHP UTF-8 cheatsheet to align it all out.