[Damon]

I'm not sure if it is or isn't. But to be honest, most salt is the same with a few different elements. With tetras, no salt is perferred though they can handle some. Its not needed. As for the guppies, they perfer harder water so salt is beneficial. If you're not going to add more neons, keep up with your regiment. Tetras (most) do not like hard water with salt and are sensative to meds. It is possible that the new ones were not healthy to begin with. You have to be careful about buying tetras from lfs. In any case now you know and you can decide what you want to add from here. Hope this helps.