a couple questions about my rainbows

hello! I have 2 rainbow fish, each with different "problems". The first question is I have a very healthy one, has a nice dark black color but has a spot on the back of his body (near the tail). It's a white/gray spot. I was wondering what this is? it doesn't seem to be getting any bigger but I'm worried it may be a body fungus of some sort. if so, what would be best to treat it with?

second question about the other rainbow fish. he seems to be a healthy fish as well but he's turned more of a grayish color than black. now, in the last week he has gained some of his black color back but is still not as black as the other one. I was just wondering if this is something I should be worried about. It is obvious that the darker one is the dominant one in the tank so could it be that the lighter one is stressed or maybe that this is just the way he is colored?

thanks!

 

Could you tell us the size of your tank and what the water parameters are please
Specifically- temp,pH, Ammonia, Nitrite, and Nitrate.
Thanks
Carol

 

Ammonia is 0
Nitrite is 0
Nitrate is 0
temp is 77 degrees
and the tank is 15 gallons.

the spot on the rainbow seems to be getting smaller today but still hasn't gone away, any ideas?

 

It could be fungus, but hopefully not. It does not appear that your tank is cycled, so keep a watchful eye on your ammonia and nitrites. I don't think rainbows are the best fish for cycling a tank and you only have 15 gallons to work with, so check your parameters everyday. If you haven't already gotten the hang of cycling, there's some articles here on FishLore that can help you with that. Go into the beginner's forum, and click on the thread "FishLore Articles for Beginners". That will help you a lot. If the white spot gets bigger or doesn't go away, please let us know and we will walk you through treatment for your fish.

 

thanks for the info...i'll give it a read!