One of my ranchus is sick. I have noticed that he is sick about 4 days ago. He stays in the coner on the bottom of the tank, sometimes slightly on its side, or swims slowly. He eats very little, not like he used before.
There is white "stuff" seen on his gills. The white stuff is not cotton-like, it is more like soft white build up.
WHAT IS IT??? WHAT SHOULD I DO??? I don't want to loose my ranchu!

Thanks

Goldguy we need you to post all the info asked above.

Then do a 30% water change this will help. Until we know the other stuff it is hard to say.

Quickly QT him. Put him in a 0.3% salt solution and add melafix. If it doesn't clear up then the problem is bacterial in nature (as I suspect).

We'll need some more info to give you a more in depth diagnosis.

More INFO:
Ammonia, Nitrate, Nitrite levels normal, Ph - 7.4-7.6, Enhim 2026 for 100 gal, UV Filter, tank 40 gal, 3 ranchus (4 inch, 4inch, 5.5 inch), feed Hikary sinking pelets, water change 2/month 40%, use AquaSafe and Gold Trace with every water change, ocasionally Alkaline Buffer.

The ranchu has white coating (not cotton like) on his gills (both sides), the head growth slightly smaller then it was. There is nothing else visible.

He eats, but lousy and rests offten on the bottom.

I know that you say the ammonia, nitrites and nitrates are normal but we really need you to post those numbers. It is valuable info that must to taking into account when trying to diagnos something, especially over the internet. Please post the numbers and we will try and help you.
Also if you could describe the "white stuff" more that would also be of help.

Amonia and Nitrite - 0 mg/l
white "stuff" is all over the gill, it is flaky. I saw several times the ranchu will move the mouth quikly and the stuff will come out of it in form of white flakes, some 1-2 mm in size

Ok thanks for the info, how about the nitrates???

The white stuff is it only on the gills? Does it look sorta like the fish has salt on it? How about the pectoral fins? Any there??
What color is the fish? I know strange question but I would like to know.

As for the stuff coming out of his mouth, I know when mine eat something they don't like........say poo flowing around or the gravel often when the spit it back out it is like a "mist of white stuff".