HELP - Fish in Distress!

[Mobile]

Yesterday I added two black mollys to my tank - one of them is sitting on the bottom of the tank with a blue discoloration around the mouth and gills behind the eyes. Appears to also be breathing rapidly. What do I do?

Tank Info:

3 days ago I upgraded from an established 10 gallon tank to a 20 gallon tank. I moved over all of the substrate, water and filters. I did a ammonia test this morning and tested only trace amounts if any.

I have a goldfish, 2 black mollies, 1 silver molly, and 1 fish which I don't know what he is - silver - upturned mouth, with an arched body. The black mollys are the only 'new' fish to the tank. My temp is 77.

EDIT: The black molly has moved to the back of the tank, floating about 3 inches up on a plant leaf, not moving too much though.

 

[Zagz]

What kind of test kits are you using, strips or liquid? I would do a water change and add dechlorinator and a bubbler if you don't have one. The established filters and substrate will help the water will not help much at all. Beneficial bacteria is housed in the filters and substrate not in the water.

Did the mollies come from another tank or from the lfs?

On a side note, unrelated but important...goldfish and tropical fish should not be housed together. Goldfish prefer much cooler temps.

 

[Mobile]

I am using a liquid test kit.

Mollies came from the pet store.


Did a water change, and I always add dechlorinator.

Already Have a bubbler.

....Molly didn't last the night, but the other one is still OK. Still wish I could know what went wrong in case it's something to do with my setup.


I am aware about the goldfish, but I have had him for over a year and he seems happy....

 

[Zagz]

It may be the mollies were sick when they came from the pet store. Keep an eye on the other molly and see how it goes. Sorry for your loss.