Urgent Care :: Shell gets brown spots when dry

[jgreerberube]

Hi my turtle seems to have a great looking shell when it's wet. However, it's a different story when he is basking and 100% dry. He has brownish spots on his shell when it's dry. What is this? What can I do to cure it? See for yourself in the photos below, I'll post the urgent care list in a minute... What I wanna know is what is it? fungus? Or algae? And how can I cure it?

[jgreerberube]

How big is your turtle? 6" or 6 1/2"
How long have you had it? Over 10 years

What is the water temperature? Room temperature? Not sure... He's been fine all the while.
Did you use a thermometer? No
Are you using a water heater? No
How much water is in there? Maybe 15 gallons (I know not enough, read more below
Are you using a water conditioner? No
Are you using any filtration? Not atm

What is the basking temperature? Not sure
Is there a basking light? No but I'm putting one tomorrow
Is there a basking platform that is easy to climb on? Yes
What kind is it or what is it made out of? Rock
Is there a UVB light? Yes ExoTerra Reptile UVB 100 - 26 watt

What have you been trying to feed it? ZooMed pellets and romaine lettuce and dandelion leaves
When was the last time your turtle ate? Today

How big is the tank/pond/enclosure? 30 gallons, which is far from enough, I know. I'm placing him in a 110 gallon once I free it up
Is the tank near a window? Yes... does that matter? What will it do???
Is the tank in a room with a lot of activity? No

Have you read the Basic Care section? Yes ages ago
Have you searched the forums for similar situations? Yes I couldn't find anything like this only algae and fungus and I'm still not 100% sure it's one of those

Is there any other unusual activity/symptoms? brown "splats" or spots on his carapace. Other than that, he's in great health, has a wicked appetite and basks a lot but is also in the water lots too, he's fantastic.

[jgreerberube]

Would like to know please... I wanna help him asap

[steve]

I don't think it's fungus. Has the turtle shed recently?

[jgreerberube]

No! I haven't even noticed that... What does this mean? Should I help him shed somehow?

[steve]

It might just be a start of shedding. It might also be an infection. Those are usually taken care of by themselves after a shed or two but it's early for me to tell.

[jgreerberube]

Ok thanks. I'll wait and see, hopefully it goes away.