Question about salt water in freshwater aquariums

[Vegan Peaches]

I have an Angelfish and 4 Mollies in the same aquarium because I was told they are all freshwater fish by the guy at PetCo. I got into an argument with a friend earlier who was 100% convinced that angels were marine fish - and he found a site that said they are. The Angel isn't looking too bad, but I still feel like a heel for putting her in a freshwater aquarium if she isn't supposed to be. I was wondering if I could add some salt to the water to kind of make is a little even, or if that would just make all the fish really stressed. Thanks for the help ^^

 

[Vip]

There are FreshWater Angels and also marine angels, i dont think you have marine angels in your tank or else they would be dead by now. Can you post a pic of what the angels look like?

 

[Vegan Peaches]

She's black, so I can't good a good picture with my crappy camera x.x

She's roughly 2 inches from haed to tail, is taller than she is long, has 2 long fins that hang from her upper body area along with the big fins that make her really tall. If that desciption isn't good enough, I can find a picture of an angel somewhere else that looks like her.

 

[Vip]

if its taller than what is it longer then it is freshwater 100%