Platy Sitting On Bottom Of Tank

[Ryandsimmons]

For a few days now one of my platys has been sitting on the bottom of the tank, barely moving. All the other fish in my tank are lively as ever and the listless platy looks healthy as ever apart from the sitting. When feeding it runs around only slightly less than normal. Is this something to worry about? It used to be a really lively fish.

All other fish are good, no signs of illness and water seems great.

Details are:

120 litre
0 ammonia
0 nitrite
20 nitrate
7.6 ph

Planted tank with:
2 platys
6 leopard danios
1 black skirt tetra
8 cardinal tetras
4 serpae tetras
2 clown plecos
Lots of cherry shrimp
Too many snails

Many thaks
Ryan

 

[WILDER]

What test kit are you using?

Does the fish look pale or darker in colour.
Does the fish look bloated or thin.
Does the fish tilt to oneside when resting.
What does it look like when the fish goes to the toilet.
Can the fish maintain balance when swimming.
Does the fish act listless and lethagic.

Darting can mean, bad water quality, toxins, overdose of meds, parasites, bacterial, the fish is dying, ph shock, stray voltage.

 

[Ryandsimmons]

What test kit are you using? - Api liquid test

Does the fish look pale or darker in colour. - Nope looks fine
Does the fish look bloated or thin. - Nope, looks fine
Does the fish tilt to oneside when resting. - Nope
What does it look like when the fish goes to the toilet. - Same as always, long brown strand.
Can the fish maintain balance when swimming. - Looks fine when it does decide to swim
Does the fish act listless and lethagic. - Yep, just sits on the substrate most of the time.

Darting can mean, bad water quality, toxins, overdose of meds, parasites, bacterial, the fish is dying, ph shock, stray voltage.

 

[WILDER]

If there no symtom of parasites I would take the bacterial route.
Can you isolate the sick fish for treatment.