There seems to be a serious condition with the "2nd turtle". If he/she is swimming lop-sided, it is usually a sign of a serious respiratory infection, in which you should immediately re-examine how you have your setups configured and contact a qualified vet. Excessive basking is not hibernation, and can be an indication of illness (more the reason to suspect a respiratory infection.)
http://www.redearslider.com/index_basic ... .html#vets
here is a brief guide for new owners:
http://www.redearslider.com/res-guide.pdf
here is more information about RI:
http://www.redearslider.com/index_health_1.html
If there is an illness or a significant difference in size, then they should be kept in different enclosures.