Hence the relatively small projected sea level rise by the year 2100, as compared to the changes measured in tens of meters that occurred in Earth's history (see Introduction). The rise by 2100 is only a small beginning of a much larger, multi-century response of ocean and ice sheets to elevated global temperatures.
Single Speed Pool Pumps: Runs at a single speed, 3450 rpm (revolutions per minute). Imagine if your car ran at 3450 rpm - all the time, and how much gas you would use! Dual Speed Pool Pumps: Have a fourth wire coming into the pump, the low speed wire. This allows you to run the pump on low speed for 8-16 hrs per day, and high speed for 4-8 hrs. Variable Speed Pool Pumps: Operates at many speeds, programmable and self-optimizing for the highest energy efficiency and greatest energy savings.
The higher the flow rate, the higher the pressure will be for a given plumbing system. The larger the pump HP, the higher the flow rate and thus the higher the pressure will be. 17-20 PSI is not unusual by any means for a pool. I run at about 19 PSI with a 1 HP Northstar pump (SF = 1.85), 2 1/2 suction plumbing and 2 return plumbing. With the solar system on, the pressure rises to about 27 PSI.