Why Aquasky only fills Pure Nitrogen in the Pressure tank?
We can use the car tires as an example.
All tires lose some pressure over time from the gasses within them permeating through the tire rubber. Nitrogen does this about 40 percent slower than regular air, according to Chemical & Engineering News, and this results in more stable tire pressures over a longer period of time. Oxygen also reacts with the tire rubber as it permeates through it, which leads to a thermo-oxidative process that degrades rubber over time.
Racers also figured out that tires filled with nitrogen rather than air react less to temperature swings. Gases expand with heat and contract with cold, which is why your road car’s tire pressure warning light usually comes on when colder fall temperatures hit. For racing teams, using nitrogen means their tires will have more consistent inflation pressures during a race as the tires heat up with use. When you are tweaking a race car’s handling with half-psi changes, that is important.
The same idea can apply to the water circle of the pressure tank. The key to the pressure tank that can storage and delivery the water to the system is the rubber diaphragm and the pressure against the rubber diaphragm. The Nitrogen can have the pre-charge pressure lose 40% less than the regular air, and the nitrogen can keep in a very stable pressure in cold and hot temperatures. The Stable pressure inside the pressure tank is also the key to the efficacy of the pump circle. The pressure tank filled with nitrogen can save 45% more water circle than the pressure-filled with compressed air.