Urgent Care :: Black spot might be shell rot

[groovy]

Hi all. A couple weeks ago I was having fungus issues with my turtle. He was dry docked and treated for a week or so, and everything cleared up once he shed. When I came back from a two week long trip, my turtle's shell looked like this : http://i.imgur.com/WLGY22t.jpg
http://i.imgur.com/Wdccsch.jpg
Under the light it seems minor but there is a spot that is darker than usual. This is one of the problem spots that I had to deal with when he looked like he had a small bout of fungus.
The black spot doesn't appear to be spreading, but it definitely doesn't look normal. Doesn't smell, isn't soft or leaking whatsoever. I assumed that it's slightly indented/scarred because I made the mistake of helping the topmost scute off, and he has several retained scutes. I'm not sure though, and I'm very worried that this might be a case of shell rot. All he ever does lately is sit under his basking lamps (pretty much all day long) and I dry dock him overnight.

I can take him to the vet if absolutely necessary, but I would rather get some more well-informed opinions before I spend the money. Normally, I would take him right away but I am in a very tight money situation and I honestly don't know enough to make my own decision.
Basically what I'm asking is, what do you guys think / do dark spots like that always suggest shell rot?

[steve]

Could that area have been injured before? Did you peel back scutes over that one? In some cases it could be a sign of an infection under the scute, but these slight color changes are not straightforward. Extremely careful observation is required right now.

I'd also cut down on pellets/protein as it looks like his growth is a bit fast.

[groovy]

I only peeled the top scute off, but that was when he had fungus/deposits. I feel really awful about that. Here are some pictures underwater where it looks a little more drastic :
http://i.imgur.com/t8CG65Z.jpg
http://i.imgur.com/GABOWYn.jpg

In case it is shell rot, should I just be looking for further indentation / spreading ?

[steve]

Is there a little white spot in the corner? Do you know what that is?

You should always look for spreading and any changes really... color, texture, odor, etc

[groovy]

It doesn't appear to be there anymore. I think it's neosporin that I didn't wash off. :p

[steve]

OK, that's one less thing to worry about

[groovy]

Update : I'm not as worried anymore. As he continues to grow, his darker markings are more uniform and make that spot look much less jarring. Looks like it's healing over since I peeled off the scute when it wasn't entirely ready I'll continue to keep an eye on him. Things are looking good, though

[steve]

So, things are............ groovy? Glad he's doing better