Today we made Brackish water. First, we added gravel with bacteria in it so the bacteria can decompose the animals the die. Next, we chose a rock to put in the shrimp habitat. The rock also had bacteria in it. Then, we mixed sea salt and fresh water in a big bucket. We measured the water with a hydrometer to see if the gravity was in between 1.0006 and 1.0008. The gravity of the shrimp's water when it was in the pond was 1.0004.