Something is up with my male guppys tail...

Question
And I can't pinpoint what it is from browsing online. I brought him home on Saturday (Nov 3rd) and all was well. My tank has been up and running for about two or three weeks prior to me bringing him home. I also bought several other guppies, male and female, some neon tetras and Pakistani loaches, but none of them seem to be aggressive or even showing similar symptoms. His tail was a light blue, but now has a colorless streak down the middle from the start to the edge of his tail and the edge looks ragged. He's definitely not as active as the other guppies, but not dead to the world, just listless. I've quarantined him just incase he's infectious. I'll send you a link to a picture of him, but I hope this is enough information. I don't want to loose him! Thank you so much!

Answer
It sounds like he has tail and fin rot.  It's treatable with medication.  It can be treated with Tetracycline, Kanacyn or Maracyn2.  Keep your eye out to make sure the others aren't showing signs.

Please keep in mind that most of these problems stem from poor water quality.  Proper tank maintenance and weekly cleaning are an absolute must in order to keep a healthy tank.  Check this site out on how to properly clean a tank:  http://www.americanaquariumproducts.com/Aquarium_cleaning.html

If I can help you out any further, please write me back.

Good luck!!   ;o)