Why does the spa water lower when the pool pump turns off and why does the spa water level go down while using the spa if the spa water is approximately 16 inches above pool water level?
The check valve between the spa and the pool is defective.
With an altitude above sea level of 2,240 meters (7,349 feet), the oxygen levels in Mexico City are much lower than normal (levels are approximately 20% lower than those found at sea level). This became a difficult issue to overcome for several athletes, especially those who participated in endurance events, such as Marathon.
Hamilton is 290 feet [88.39 m] above sea level. Actually Hamilton is, somewhat uniquely, divided into 2 sections because of our escarpment running the length of the city, dividing it into lower and upper sections. The lower part of Hamilton is approx. 246 ft above sea level, and the higher is approx. 777 ft above sea level. I'm currently writing this from the higher (we call it the 'mountain').
First understand that the boiling of water occurs when the energy of water molecules is equal to the vapour pressure... (i.e energy of water is equal to the external pressure due to the atmosphere)... above sea level the atmospheric pressure is lower hence low energy is required... hence water boil at low temperature...
At higher altitudes, water will come to a boil at lower temperatures than at sea level. The pressure at 10,000 ft is 20.58 inches Hg, and so the boiling point is 194.7 °F. See the Related Question link to the left of this answer for more detailed information "How does the elevation affect at what temperature water will boil?"
I learned the answer to this in science this year, so don't worry, it is accurate: The higher above sea level/elevation you are, the colder the temperature becomes. The reason for this is because there are air molecules in the air bump closer together when you are lower above sea level- that creates warm weather. The higher above sea level you go, (for example, the tops of mountains,) the more separated and spaced out the…
You are probably above sea level so that the atmospheric pressure is lower than sea level pressure. Water boils at lower temperatures as the pressure is lowered. The other possibility is that the thermometer is not calibrated correctly, but I'd go with the atmospheric pressure is below sea level pressure.