Gray patches?

[Goldiegupp]

My black moor is recovering from stress and I've noticed he's got these gray patches on his body and his tail that are too big to be ich. Is it fungus or something? What should I do to treat it?

 

[littletankbigworld]

I can say that I'm 99.99% that there is nothing you can do to help your fish until you upgrade all of your 5 goldfish into a much, much, much larger tank, say 150 gallons or more. I know you want to upgrade slowly, but it's really unhealthy to cram all those goldfish into a small space. Plus, it looks like you added more goldfish since I was last on this forum. Having 4 goldfish in a 10 gallon tank is like living in a closet with 4 other people and never being allowed to leave to use the bathroom or receive medical help. I advise you to purchase a monster-sized tank or pond or sell all of your goldfish to someone who has enough room to properly care for them. If you are really attached to your fish, I would get rid of all of your goldfish but one. Sell both of your 15 gallon tanks and buy a 30 to 40 gallon tank for your single remaining goldfish. And, of course, cycle the tank.

 

[littletankbigworld]

For now, you can add your black moor to the empty 15 gallon. You will have to do a fish-in cycle, which will be very stressful and might kill your fish if you are not careful with testing the water and performing water changes, but this is a better solution than to keeping your fish in an overcrowded tank. You still need a bigger tank (bigger than 40 gallons) for your fish to recover.
Just out of curiosity, what are your readings for ammonia, nitrite, and nitrate in the overcrowded 10 gallon?

 

[misterking]

+1 on everything LTBW said.

Your tank is ridiculously over crowded, even with the fish at a small size. You have 2 options; upgrade to a huge tank, or sell some fish on.

A 10 gallon is NOT appropriate for goldfish. I'm sorry but it's the only way your problems will start to get sorted.