Molly Just Lying On Ground, Dying?

[cormack12]

Hi, need some HELP!!
 
I noticed earlier that one of the mollies in my tank was swimming round the tank almost vertically with his head down and tail up. I've just checked him again and he is lying stationary on the aquarium bed. Not really sure what to do. Things of note:
 
25l of 70l water change yesterday (treated)
Ammonia: 0
Nitrite: 0
Nitrate: 0
Temp: 26C/79F
 
4 x eleocharis parvula planted and one piece of large bogwood with a live plant that seems to be thriving. The parvula is only two weeks old and also has introduced one snail that I can see.
 
Both other mollies in the tank seem fine. I have only ever noticed the white mollie a bit more aggressive chasing others round the tank. Diet has been tropical fish flakes and a small amount of boiled carrot infrequently.
 
Picture of sick mollie:

 
Picture of other live mollies:

 

[noobgamers]

i sadly think you may be right

 

[WILDER]

Does the fish look bloated?
Is the fish also struggling to swim and stay upright, Have trouble getting off the bottom of the tank, or top?
Signs of swim bladder can also be headstanding, or standing on the tail.
Floating upside down.
What do you feed your fish?
What type of test kit do you use?
 
A link to swim b;ladder disease.
http/www.fish-disease.net/diseases/swim_bladder_disorder.php

 

[spencer_41188]

unfortunately, yes it sounds like its dying, I lost 2 mollies that way to a fungus, almost a 3rd, but managed to get the medicine and save my favorite molly, which is a male cream-sicle Lyre-tail