Today we made the salt water, put in the gravel, and chose a rock that had algae on it. First, we took out our glass containers and chose a rock with algae on it. Next, we put cinders on the gravel. Then, we filled a bucket of water and put salt in it. Finally, we put the salt in it, mixed it up, measured it with the hydrometer, and made sure it was 0.06 in salt.