On Walls.io we never delete old content automatically. This means, when you delete or change the sources of the wall (hashtags, profiles, etc.) the old posts will still be there. Instead of deleting them, we keep that content and just add new posts matching the new configuration.
When you delete a source however, you are offered the opportunity to delete all posts that came from that specific source:
If you decide to delete those posts at a later point in time, you can do so by using our "Delete Outdated Posts" option. You can find that in Settings > Danger Zone:
Attention: This will delete all posts that are not originating from a currently active source (hashtag, profile, etc.). If there are some posts you want to keep, don't use this button! Instead, go into your Walls.io backend, click on the "Moderation" tab and hide all posts you don't want to show instead.