Hello, I have two guppies, Mr. Darcy and Holden Caufield, in a 2 gallon tank. Mr. Darcy, I have had since Sept. 2 and Holden Caufield for about 3 weeks. I have been worried about Mr. Darcy for awhile now. He was alone for awhile but now seems happier since the arrival of Holden Caufield. He is not listless anymore and seems to swim and play beteter. He seems to eat better too. But his coloring is not as good as it used to be and his tail is seems like it's getting smaller and doesn't flare out anymore like Holden's. Mr. Darcy is supposed to be yellow with a flame orange tail but now he looks lite yellow to white and although his tail is still orange, it just doesn't look right. Holden seems fine. He is bright yellow with a bright yellow flared out tail. My concern is for Mr. Darcy. I just don't know why he seems to look worse and worse. I don't believe he has ick. I don't really see any white spots. I haven't checked the ph level of my water but I plan on buying a kit today. I am using just regular tropical flake food. I try to change the water every week and usually change replace about 25% of the water. Sometimes I go two weeks though. I just need to know if Mr. Darcy is sick with something and if so, do I need to worry about Holden or what??? I am confused. I haven't had fish in years and don't really know that much about them. I guess I thought you just put them in a tank and feed them. Kinda stupid I know. Any advice, ideas is much appreciated. Thank you.