When I download torrents that contain multiple sessions of a show I only download one season at a time and delete each individual show after I watch it due to limited space on my PC. When I am nearing the end of one season I start downloading the next. When the next season is downloading I am not able to delete from the current season. Is there any way around this?

Inside Tixati, select files and set priority to Off (right click > Priority > Off), delete files using right click > Delete.