Help. My Plattys Have White Stuff Growing On Them

[Sneer]

Please tell me what this is and how to get rid of it.
I don't know if it is ICH or parasites or what.
I have 4 cory catfish and 3 plecos as well. So I'm not sure if using medicine is safe. Thank you.

 

[fluttermoth]

It's not ich, nor does it look like parasites. It's hard to tell from your pic, but is this white stuff on the body of the fish, or on the fin? Is it fluffy looking or solid? Is there any redness around the white area?

 

[Sneer]

It's on one fish' fin and white spots on a second's body. No redness or swelling, just white bumpy parts

 

[fluttermoth]

If it was ich, it would look like the fish had been sprinkled with salt; very small, bright white, slightly raised spot.
 
I think I'd recommend an antifungal, but use it at half dose, and check the label carefully; some meds you can use at full dose, even with cories and plecs.