Help with sick silver molly

[Something based]

Hello, the silver Molly I have, has had issues since day one and I was hoping someone can help me decided what to do. Something to note is this tank is a brackish water tank that I try to keep between 1.007-1.015
I thought she was pregnant about 2-3 weeks ago due to a dark gravid spot. Given all of these new symptoms I am concerned.

I did a water test and only thing high was nitrates so I am currently doing a water change and that’s why the water is so low.
The other silver Molly I have, recently started breathing fast And heavily. Also not as active as he used to be. I do also have a black female Molly in this tank that that I think might have a fungus on her mouth?
Please help I’m not sure what to do

 

[Colin_T]

How long has the tank been set up for?
How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?

What sort of filter is in/ on the aquarium?
How often and how do you clean the filter?

What is the ammonia, nitrite & nitrate of the water (in numbers)?

What is the pH, GH and KH of the water (in numbers)?
If you are using tap water for the aquarium, you can contact your water company (via their website) to find out the GH and KH. Look for a water analysis report and the info will be on that. Pet shops can also test it for you if you can't get the info from the water company and don't have a test kit.

How long have you had the fish for?
What symptoms does the silver molly have that concern you?

The white on the black molly's mouth is probably excess mucous. There is a disease called Columnaris (mouth fungus) but it doesn't normally occur in water containing salt (brackish aquarium like yours). Fish naturally have a thin layer of clear mucous over their head, body and fins. It provides a layer of protection from parasites and disease organisms in the water, along with helping them move through the water easier, and offers some protection against chemicals in the water. When the fish is stressed from poor water quality, chemicals, or diseases, they can produce more mucous and that can look like a cream, white or grey film over all or part of the fish. I wouldn't worry too much about the white on the mouth unless it spreads over the head and face, then post pictures asap. But chances are the big water change you are doing now will get rid of it by diluting the nutrients in the water.

 

[emeraldking]

You've mentioned from day 1... it could be that this silver molly came out of freshwater and got stressed by entering brackish water. Not all specimens get adjusted to brackish water that easily desapite of the fact that mollies can be kept in brackish water.