my mom has 2 goldfish and i think they have ammonia burns. they have red marks on them since she did a water change yesterday but the marks didn't appear until after the water change. she is insisting it's from the clean declorinated water she added because you aren't supposed to clean the water. i am waiting for her to email me some pics. my daughter is very upset(she lives with them half the time) and she called me saying Gramma made her fish bleed. they are in a ten g that i finally got them to take. they were in a 2.5g until a month ago and it was really hard to talk them into upgrading. i tried to give them either a 30 or 20 but they said it was too big because the pet store lady told them they could keep them in 1g each. grr..... anyways, i'll post pics in a minute hopefully. is it possible for amonia burns to appear after a large water change?