We prepared our brackish water (salt and fresh water) for our opae`ula habitat. We first got the decomposers into a tiny teaspoon and put it into our opae`ula habitat. Then, we had to choose a rock to put into our habitat. Third, we had to fill up the vases one full and one halfway because one full and one half is three half and that could be half water for each of our vases. Then, we sprinkled salt into our bucket that held our water. Fifth, we had to mix up the salt water and fresh water to make brackish water. Sixth, we had to use the hydrometer to see how much salt and water we have to put in and we had to do the gravity 1.006. Lastly, we had to equal the water to our vases and we put it in the water.