Join Date: Oct 2010
Location: Victoria, Australia
I replied on your other thread but now I know why you were asking. There are special 'conditioning salts' that are intended for use with livebearers but it seems like other people just use normal aquarium salt.
Most livebearers do like harder water, so adding crushed coral to your filter can also help to raise the hardness and pH of the water. While it can take a little while for it to have an effect, it is often much safer for the fish than some products that only work temporarily.