Today, we prepared the brackish water for the Opae`ula habitat. Brackish water is a mixture of salt and fresh water. first, we put in a tiny teaspoon of decomposers in the habitat and mix. Then we got to choose a rock for the habitat! then put one-in-a half vases of water. then put the salt in. Next, mix well or until the salt dissolves in the water. Then, use the hydrometer to see the gravity of the water which is supposed to be 1.006. Once it is correct, yo can pour brackish water up til its half way. and its done!