First some background info. We received 2 YBS from a friend. Part of the time he had them both in a 40gal tank, but it had pink pebble substrate. They were then eventually moved to a 20gal tank so they would fit in his daughter's room who the turtles were actually purchased for. This tank had regular tank gravel. The tank had a basking area but only a heat lamp no uvb, it had a 20 gallon filter but probably just enough water to cover the turtles. It did not have a water heater.

Present day: As of this morning the turtles are eating, one basked for a couple hours when we brought them here but has not sense going in the water. The other has not basked to my knowledge sence getting them. The one not basking really needs to as it shows signs of improper shedding and needing the UVB. The plus side is they are both eating. The uvb covers the tank so it is still getting UVB. We are working on figuring out how we want to cover the basking area to make it more private and so they can feel safe. They have pooped about 6 or 7 pink pebbles from their original tank sense being in our tank (it varies but sticks around 78F).

Edit: spelling and information clarification. All my post are done from a phone.