My female molly use to be jet black but after treating one of my other fish with costapur (had the lights off for 3-5 days) i noticed she was looking a bit "faded"
and now it looks like her side and bottom fins are turning whiteish?

Ive just read the "mollies need salt" and am sh#tting it she has finrot or something she still seems perfectly happy.

Also, my lfs lady told me cooking salt was ok for them but i only added it once, cant remember why.

I feel a bit in the dark now, are my mollies going to be ok living in freshwater?

Cooking salt is definitely NOT okay because of the iodine. Get some acquarium salt instead.

Do you have a picture of her - it would be easier to identify (or try) what is wrong?

What are your water stats?

I dont know how to get pics onto this laptop, dont know it would show up well on a photo.

what about the rest of my fish, what if they dont like salt? i have swordtails flame tetras and a fighting fish.

i`ll get my water stats up soon

I have swords, mollies and tetras and they are all fine with salt. I believe you have to watch scaleless fish like loaches with it. Plecos will also be fine.

My water stats are fine, Ph is around 6.8-7.0, everything else is 0ppm

I got a male sailfin last week and this morning he was harrassing her like hell, going for her bum area but she is giving as good as she gets at times, she isnt pregnant as far as im aware

hope she is though