How to get photo moved to another album on iPhone 5c?

I know how to make new albums and add pictures to them, but once I move the photos into a different album they stay in my main photo roll. How do I remove them from the main and just have them on my custom album? (iPhone 5c)

You can't (my frustration also) All of the pictures are referenced to the Camera Roll and all you can do is control the display of a subgroup by putting them in albums and try to keep people from looking in the Camera Roll if you have images awkward from some viewers. If you delete from the Roll, they go away in all the sub-albums.