Balloon Molly Looking Thin!

[Sasha]

Over the past few days, I've noticed that my female balloon molly looks thinner than the male. Is this normal? I feed my fish three times a weeks and the water tests out fine. She's eating perfectly and swims normal, but sometimes hides in teh corner of the tank. My male balloon molly looks really fat compared to the famale. Just behind her fins, her belly looks sunken in a little but I don't know what it is. Any advice?

This month I've been experiencing an unsolved probelm which ended up in me losing more than half of my fish. The other fish in the tank look normal and they don't bother any other fish. The tank has been establisheed for over a year and contains a heater and an Aquacler 200 filter. I do weekly water changes (about 20%) and try to keep the tank as healthy as possible. I don't want to lose this little balloon molly!

 

[HeatherSweetness]

Have you tested your water parameters since you've had this problem?

 

[Sasha]

I brought a water sample to Petco yesterday so they could test the water and it tested out fine. Cleo's still clinging to life, but barely!