UTF-8 How to change it?

hi, noticed today that some characters like á é í ó ú are not showing properly in my site, looked for the reason and found that the default elgg  encoding comes with charset=UTF-8

someone told me to change it to ISO-8859-1 which looks to fix the problem with accents, so wonder if someone can show me which file is managing that encoding n elgg to change it accordingly

thanks in advance