Urgent Care :: Shell Rot???

[AngelaBordelon]

I'm new to the site and was impressed with the amount ouf knowledge most of you possess about your turtle friends. My turtle Gnarly has not been sluggish or sick but has some kind of discoloration on his shell. I was hoping someone on here may be able to help him. I provided info and a picture bleow. If you need any more info please let me know. Any insight would be much appreciated Thank you,
Angela

How big is your turtle? - 2 inches
How long have you had it? - 3 years
What is the water temperature? - 74 deg
Did you use a thermometer? - yes
Are you using a water heater? - no
How much water is in there? - 18 gallons
Are you using a water conditioner? - Tetra Fauna Repto Gaurd
Are you using any filtration? - Turtle Clean 501
What is the basking temperature? - 90 deg
Is there a basking light? - yes
Is there a basking platform that is easy to climb on? - yes
What kind is it or what is it made out of? - Plastic floating basking area 7"X12" Very dry Area
Is there a UVB light? - yes

What have you been trying to feed it? - Banana, Dandelion leaves, pellets, red wigglers calcium powder on food, Baby Platys (Doesn't eat them much)
When was the last time your turtle ate? - No

How big is the tank/pond/enclosure? - 40 gallon
Is the tank near a window? - No
Is the tank in a room with a lot of activity? - No

Have you read the Basic Care section? - Yes
Have you searched the forums for similar situations? - Yes

[steve]

Most of what you see is shedding, but I can't tell of there are any other shell issues.

You do want to try to maintain a stable temp (around 77F) with a good heater. Does he eat pellets or live prey?