Deleting from document directory only deleting half of saved data - ios

Question

I am saving a video to the document directory. When I take a video with the app, the amount of space the app takes up goes up, but then when I delete the video from the document directory, the amount of space the app takes up only goes down half way. For example the app takes up 1.2MB and when I take a video, it goes to 20MB. If I delete the video, the app only goes down to 10MB, not all the way back to 1.2MB as it should.
Here is the code I am using to save the video:
NSData *videoData = [NSData dataWithContentsOfURL:self.videoURL];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *tempPath = [documentsDirectory stringByAppendingFormat:#"/vid1.mp4"];
BOOL success = [videoData writeToFile:tempPath atomically:NO];
And here is the code I am using to delete the video:
//Delete Video
NSError *error2 = nil;
//NSData *videoData = [NSData dataWithContentsOfURL:self.finalURL];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *tempPath = [documentsDirectory stringByAppendingFormat:#"/vid1.mp4"];
BOOL success = [[NSFileManager defaultManager] removeItemAtPath: tempPath error: &error2];
if(!success)
{
NSLog(#"error from removing item at path %# is %#",
tempPath, [error2 localizedDescription]);
abort();
} else {
NSLog(#"Video deleted");
}