Trouble with Molly

Question
Hi Nathan,

I have a 22 gallon tank and currently have 4 adult female mollies, 5 small molly fry, 2 small catfish, and 3 red platys.

One of the female mollies hasn't been doing well for a few days now. She has been spending a lot of time resting on the bottom of the tank. When she does swim around her tail seems a bit stiff and when she's at rest it kind of droops down so that her back looks arched and her sail fin is pretty closed. When she's not swimming she kind of just floats to the bottom. Yesterday her fins looked pretty clamped up, but today she is waving them around a bit better but still rests on the bottom a lot. She did eat when we fed them frozen food yesterday, so I thought that was promising but she doesn't seem to have improved much today.

Any suggestions as to what I could do?

Thanks in advance,
Stephanie  

Answer
Hi Stephanie,

I'm extremely sorry for the slow response. I've been quite busy the past two days...

Anyways, is your Molly showing any outward signs of disease? If it's just the clamped fins, it may be stress. Try adding some aquarium salt to the water, if you are not doing so already. Mollies prefer to live in a freshwater aquarium, with a little bit of salt added. One or two tablespoons of aquarium salt (not Marine salt) should do the trick.

If you see any other signs of infection, don't hesitate to give me a response. For the meantime, perform 20% water changes every 2-3 days, until her condition improves.

Good Luck, and I hope your fish recovers!