Since I got to the aquarium super early today, I was able to spend a little more time with my tank. I began by taking the water quality. What i noticed was that the level of ammonia and nitrites had gone down to zero and the salinity had gone up. This confirms that my tank is following the nitrogen cycle. If you look at the chart (below) you can see how my tank is behaving exactly as it should. The salinity had gone up because the water is evaporating out of the tank as a result of the very warm temperature of the water. When saltwater evaporates from a tank, the water level drops, but the salt stays behind which causes the salinity level to rise. If the salinity level rises to much, the fish will not survive. This problem can be solved by adding fresh water to the tank to balance out the salinity. I think the most important element in maintaining a fish tank is to make sure all the water levels are kept at the correct levels. Later in the day, I was able to feed the octopuses today. I fed each of the 3 octopuses little pieces of shrimp. Just like last time, I did this by putting the food at the end of a zip tie and making them pull it off. The tricky part is that you have to get the zip tie out of the tank before the octopus grabs the zip tie and the fish. One reason that the octopuses are fed this way is because they are so cleaver and can figure out how to take it off. Some octopuses have also learned how to open childproof pill bottles. Octopuses are cleaver animals that need to stay stimulated.