Heroku SSL with exceptions

Question

I am using Heroku SSL and I need one of my Rails controllers to not use SSL.

I tried a before_filter in my controller:

if request.ssl? && Rails.env.production?
  redirect_to :protocol => 'http://', :status => :moved_permanently
end

Unfortunately, this ended in a too many redirects error. How can I create an exception for this controller? Thank you very much.