Alyxx said:There are quite a few that will do will in low brackish conditions. Java fern is one. Mangroves do better in higher salinity, I have some actually. For mollies, I would aim for a lower end brackish tank, maybe up to 1.010 specific gravity. I don't think mollies like it much higher than that.
Actually, to be honest, mollies are native to both brackish water estuaries and coastal areas-they can survive in a complete marine environment if acclimated slowly.