I'm a first time poster and have only just registered. About a month ago i had my 4 goldfish and a pleco in a 10Gal tank, yes bad i know. Well about a week later you probably know him as cdsang, we're related, visited me and before he came he bought me a Magnum 350 canister filter, and while visiting he bought me a 55Gal AGA tank and stand, what an upgrade. Well we ran ito a bit of a snag when my well water did'nt want to cooperate, the water was soooo filthy. So we decided to put the canister filter on the 55Gal in hopes it would clear up the water. A week later the water was clearer than it used to be but i was still unsure about puting the fish in yet untill later that night when i went to go feed them i noticed 2 of my goldfish had spots of fadeing color by this i mean they went from orange to spots of white. Well faster than you could say Quidditch i got out my trusty fish net and put them in the 55Gal. They are fine now but the same fish still have fadeing. Whats wrong? What can i do?