Male Guppy "flaking"
 

HEy guys I'm new to Forums, but have had fish for years, I Have a male guppy that looks like the has swollen gills, and the entire area is redish, I have been looking through the forum, but haven't seen anything close to this... please help
40 g
15 guppies
1 pleco
natural plants

A picture and water parameters would help a bunch as Lupin suggested.

I'm almost betting this may a fluke problem. What do the insides of the gills look like? Any sores, holes, white streaks, or greenish color?

Looking better/different
 

Well I can't seem to be able to take a picture of him, b/c of the glare, how should I take it?? Also it seems that the problem is more of his side fins being swollen/flaking, reddish pink, and he is holding one fin out... I recently cleaned this 40 g, so all the fish were temporarily in a 10 g...

Re: Looking better/different
 

I use flash when taking pictures. Try putting your lens against the glass of the tank, that way the flash has no glass to bounce off of and hit the lens.

You can also try and trick your camera, but this doesn't work as well on aquariums. Get a thick piece of paper.. or something that will block the light. And use your camera in flash mode, but have the flash blocked with your item. Be warned this will throw a really bright light back at you.

Tank cleaning
 

I cleaned it using vinegar, and I know this sounds awful, but I have never tested my PH or anything like that, I have live plants, large "creek gravel" and several flat large rocks, I have never had a problem with my fish before. What kind of tests should I do??