Platy Getting Picked On

So recently my platy has been seeming a little different. She still eats fine and swims fine however one of her fins is torn and it looks like fin rot. However my water levels are all 0ppm and nitrate is 5-10ppm. I am not sure if the tear is from the other fish picking on her or if it is something more serious. She also seems thinner and her fills are a little inflamed.

 

Try and find the bully, lower the temp a degree or two to curb aggression. Are the gills red at all?

 

Try and find the bully, lower the temp a degree or two to curb aggression. Are the gills red at all?

They are slightly red

 

Redder than normal?
On the damaged fin, is the edge of the tear red or white, or any color that doesn't belong on the fish normally

 

Redder than normal?
On the damaged fin, is the edge of the tear red or white, or any color that doesn't belong on the fish normally

Yea a little redder than normal. The edge of the fin does not appear to have any discoloration

 

I don't know why the gills would be red, your parameters are all good
So that tells me the fin either split, or is getting nipped, can you get a picture of it?

 

I don't know why the gills would be red, your parameters are all good
So that tells me the fin either split, or is getting nipped, can you get a picture of it?

It’s very hard for me to get a clear pic. She is still being very active so that is good. I believe it may be from getting nipped. Is there anything I can do to stop the other fish from doing that?

 

Usually there's not a lot you can do. Is it like a male picking on a female or something? Male against another male?

 

Usually there's not a lot you can do. Is it like a male picking on a female or something? Male against another male?

Female against another female

 

Usually there's not a lot you can do. Is it like a male picking on a female or something? Male against another male?

You mentioned lowering temp before. My temp rn is about 78 degrees

 

That's the only other thing I can think of, drop it to 76 over a few hours, 75 at the lowest

 

That's the only other thing I can think of, drop it to 76 over a few hours, 75 at the lowest

Ok thank you