I have a 40 gallon brackish fish tank with the salinity around 1.005. I am looking to put in a variety plants. I currently only have Ferns. I have a puffy fish, 4 Scat Fish, and 1 parrot fish. Any ideas of what would be good so that the fish do not eat them. They seem to leave the ferns alone. any other plant I put in lasts maybe a week if I am lucky. I have black sand for substrate.