Reduce memory usage in ionic framework

I am working on an app using ionic framework which pulls content from my backend system. I have a map as well and to reduce network usage I am saving content in module.factory (not sure if this is good for mobile app) and call api once when required. I am seeing my memory usage is almost 200mb in xcode and was wondering how can I reduce this. I was thinking of destroying scope ($scope.$destroy and also delete $scope) when each controller starts but it is not working.