does anyone know if you can put live sand and rock in a brackish water tank? i have a 55 gal tank set up and finally got it stable so my little puffer friends don't die. but now i'm considering taking the gravel out and putting sand down. i'm not sure if i can do that while my little friends are still in the tank, or if live sand and rock will even survive in a brackish water set up. the salinity is at 1.006. if anyone has any idea please let me know. thanks, jessica