Whaty disease has my sunset gouramis??

[serbanmm]

Hi all! I have a problem with my sunset gourami. I bought him1 month – 1.5 months ago and then he has not shown any sign of illness. After three or four days it appear on his skin and fins brownish-blackish patches. Since then (with 1 month ago) he doesn’t shown any changes even he’s slightly worse. However, he’s eating and swimming normally but he is a little more agitated than the other fish. I attached a picture with my fish and I hope someone to know what he has! Sorry for my English but as you noticed I’m not a native English speaker! Thanks!

PS: My aquarium: -60 litters
-heater, white light bulb, water filter
-fishes: 1 pearl gourami, 2 sunset gourami and a betta male
-5 plants
-water temperature around 82 Fahrenheit(28 Celsius)
-water parameters: 0 ammonia, 0 nitrites, 0 nitrates, PH:7.8

 

[spoonman]

Was this tank cycled? Unusual that the Nitrates are 0. Could the patch be a natural coloration change?

 

[serbanmm]

Yes it's cycled...i think that i have 0 nitrates because i have 5 plants and only 4 fishes( 3 being small ones)!!

 

[serbanmm]

I have more pictures...i hope that are more accurate!The fish looks brighter because of the flash-light!!!

 

[HN1]

FAQs on Colisa lalia, C. chuna... "Dwarf" Gouramis of Many Names, Honey, Flames, Neon Blue,  Sunset Fire... Disease/Health

HTH

 

[serbanmm]

My sunset gourami it's darken than ever...so, now he have the caudal fin almost black...and his other fins are also black....and of course that on the skin the patches are darker...so...someone have an ideea what it is??? In the same time he's eating and swimming like a shark...soooo...i'm so confused!

 

[serbanmm]

Here are some new pictures( are not so great but you can see where is the problem)!