Yellow bellied turtle that never basks

Question
Hi,
The other half and I have had this YBT since july last year (we got him as a present and he was still a baby) it took us a couple months to save up and get him everything he needs (basking lamp, basking ledge, filter, uv light and water heater) but he has had everything now since september time. In that whole time he has not basked once, he just stays in the water at all times. He is really active but he is now getting algae on his shell and his belly looks like it has pink stains on it. He has grown quite a bit, he is active always digging in his pebbles at the bottom of the tank and he eats a lot but he still refuses to bask.
Do you have any idea what is wrong with him and what we should do to help him?

Hope to hear from you soon.

Aimee

Answer
Hi,

You should check your temperatures.  If the water temperature is too warm in relation to the basking temperature, the turtle will spend too much time in the water.  It's very important for a turtle to bask at least several hours a day.  The basking temperature should be 88-90 degrees, and the water temperature should be about 76-78 degrees (a little cooler for an adult)--there should be at least a 10-15 degree difference.  If the tank is too small (less than 30 gallons), you may have trouble keeping the temperature difference.  YBS need quite a bit of room as they grow, so if the tank is smaller, you might want to upgrade to something larger.