My Favorite Platy is sick

[NewLoverOfFish]

Since I am new I didn't know when I do water changes I should add more salt to my aquarium. Now I have lost 2 platies and my favorite is not looking to good. I have done a water change and add a little extra salt this time. This was 2 days ago. My fish just kind of slowly swims around but will not eat. Is there something else I should add to the tank?

[aquariumfishguy]

Don't add "extra" anything as that can make things worse. Salt doesn't evaporate or "go away" on it's own. Water changes is the only way to loose some of the salt content and so thats the only time you should add salt.

Make sure to do water changes every week...30-40% of the water should be replaced via a gravel vacuum.