I have been checking out these forums for a while but this is my first post. I recently got back into fish, I have a 25G with underground and power filtration. When i started the tank i used cycle and aquaplus and i have real plants inthe tank which seem to be doing well. I threw 3 large giant danios in my tank just to get things started. about 2 days ago.. the fins of one of the Danios starting showing discoloration.. went from clear to sorta of a rust colour. Soon after that he was swimming upside down and so i got rid of him. The other 2 were fine until today, they seem to have developed some of the same colour... anyone have any idea what this could be. Thanks for any anwsers you can give. These forums rock!