Angel lookin crappy

[thehat]

I have an emperor angel. He acts fine and swims and eats and is the rule of the roost in the tank. For the last 3 weeks he has some crusties on the edge of his fins and his outer fins look like he is getting picked on but he is not gettin picked on at all. I was told that it was a fungus of some sort and he would be able to heal on his own, but if it got worse I was supposed to treat it. Is this right and what the heck is it?

 

[thehat]

All my levels are good. I have a little bit of Nitrate but I feed them 3 times a day sparingly. Yea i have in two seperate tanks. I have triggers and puffer and angels together. They are all very small. Gonna move them to a 120 Next Year when I move into a house perminately. I do a 6 gallon water change every week. All the fish get along super well. I know what you mean about the messy eaters though. Should I do a 10 gallon water change this week? The water is pretty dirty when I water change.
What else could I do to fix it. Could the fish die from it?

 

[thehat]

Yea white clumps on fins