Test: Check that No farms is on and the thermometer and oxygen monitor are still in the pond. Click New pond until you find a pond with a starting temperature between 20 °C and 25 °C. Record the temperature and oxygen concentration for this no-farm pond. Now, turn off the No farms checkbox. Click New pond until you get another pond with a starting temperature between 20 °C and 25 °C. Record the temperature, number of farms, and dissolved oxygen for this pond. Repeat until you have looked at five ponds.