The fish tank that I have right now is considered brackish water. It has a pH that ranges from 7.5-7.8 and a gravity that ranges form .002 to .005. To keep the pH up I have a piece of coral hidden under some rocks. The plants I put in the tank where Java moss, Java fern and white sandy, because every other plant died because of the salt. For the fish I have a small Mono, a Tricolor Shark Cat, a Figure Eight Puffer, a Bumble Bee Goby, a Clown Loach, an Archer Fish, an Upside Down Cat, a Green Puffer and four Australian Rainbows. For crustaceans I have a fiddler crab and a red claw crab.