How often should I change oil if reusing daily?
Oil does not wear out.  Unless burnt.  Try this. Drain or pour the oil into a coffee filter holder with the fine screen. Warm oil. It will remove most crumbs from the oil. Into a large mouth jar. Put lid on jar.  To supper clean oil run threw the paper filter. But that is slow to do. I do not see in America oil cans. With the filters in them of fine screen like used in small motors. Pour out remaining oil in bottom of fryer last. Wipe clean. The more crumb build up in the bottom the faster your oil turns dark as it burns.  Oil should last 6 months if filtered after use. Crumbs removed. By just adding oil lost.  To remove taste fry potatoes in it last.