Sick Angel

[McCool]

Okay, I recently got my 55 gallon tank back from my brother, as we are in the process of moving and renovating a house. I've had it back for about a week, and just noticed how poor my Angel looks. This will be rushed, and I'll try and fill out the form and add some photos tomorrow, since I'm on a phone and my Wi-Fi is down and I can't run up my data right now! It's a 55 gallon planted community, pretty low stock, no bullying. He's the biggest thing in the tank. His top fin is very nearly half gone, and his body looks a bit scraped up. He isn't acting like he usually does, although he's acting a lot better then he looks. Sorry for my lack of info, I'll fill in everything as soon as I can. Literally, all my fish supplies are in storage, which makes this pretty hard. I'll see if I can locate my test kit,however, I'm pretty low on stock and my tank is very mature with lots of live plants, and previous to moving my nitrates stayed around 10, with very few water changes. Topping off, mostly. Any ideas would be great, but I know it's hard with so little info. I do not have a QT tank. He's the only Angel in the tank, absolutely nothing to bully or nip him. Thinking he may have been scrapped up in the move, not sure.

 

[mark4785]

I will try to provide a worthy response based on the such little detail provided.
 
I think that your fish may have fin rot. This often causes the fish to stop eating and the edge of the fin that is rotting always has a visible red line at the sight of erosion.
 
Before accepting the above as a diagnosis or not, I recommend posting up your aquariums' ammonia and nitrite levels, the tanks stocking level and a picture of the fish.
 
Is your tank a low-tech planted aquarium (i.e. low wattage lighting and slow growing plants?). If not, your nitrate level of 10 ppm is not conducive to strong plant growth, but rather, encourages cyanobacteria to grow (blue-green algae). Certain kinds of cyanobacteria are poisonous so if you do suspect your fish has a wound on it's fin I would recommend quarantining it to remove it from the cyanobacteria.

 

[SarahR]

As the previous poster noted, this is speculation based on very little info.  You mentioned moving, and I think you are saying the tank has only been back up a week.  If so, the fish went from what you admit was a tank that had almost no water changes to basically a sudden 100% water change after being transported.  Yes?  
That alone would be highly stressful.  If the body and scales are marked up/missing, that does sound like trauma from thrashing about- Angels are not good in confined spaces, being not very flexable they easily hurt themselves.  Half gone dorsal sounds like fin rot as Mark above mentioned.  Many bacterial nasties can be unearthed when a tank is broken down and refilled, especially one that wasn't getting regular water changes and gravel vacs.  Angelfish thrive on water changes, you almost can't do too many but you can definitely do too few.
 
If I misread or misinterpreted your post I apologize.