Should I Get Out The Clove Oil?

[Fintastic!]

I noticed during the week that one of my platys was opening and closing her mouth rapidly all the time, not gasping at the surface though. Now looking at him, she has lost so much weight. You know when you watch a nature program about salmon and they become deformed looking, well that's what she reminds me of now. She's not swimming around much and her bottom end is lower then her top half if you know what I mean. I last did a 30 percent water change on Wednesday. My parameters are Ammonia-0, Ph-8.2, Nitrite-0 and Nitrate-20.
Firstly can anyone shed any light on what could be wrong and secondly do you think I should euthenise her?
Thanks guys!

 

[thereverendturtle]

Is it possible she dropped fry?

 

[Fintastic!]

No, I only have female platys. I'm wondering if she injured her mouth, though I don't know why she's moving it all the time. She definately wants to eat as she comes over with as much gusto as the rest when I'm feeding them. I notice her taking food into her mouth and spitting it out again. She has gone from a nice healthy looking fish to a sorry, skinny looking thing in just a week.
I really don't know what to do. She seems more energetic today than she was yesterday. I guess I'll see how the next couple of days go.

 

[Fintastic!]

Well I did the business with the clove oil. Put her out of her misery.

 

[FishBlast]

Going skinny could be a sign of internal parasites, which could have been solved with some medicine. Could also have been gill flukes, which causes an inconvenience with eating too.