When I try to upload large files to my site (150mb+), I get a message saying that I cannot upload files over 150mb. Is this something I can change on Reclaim Hosting, or does it have to do with the application I am using?
That’s a server setting. For anything over 150Mb you’re going to want to use FTP. If you’re using WordPress you can use this plugin to import media that was uploaded via FTP to the account Media from FTP – WordPress plugin | WordPress.org.