1.  You must read the pressure gauges while the system is running to get a true picture of how the filters are doing.

 2.  When you see a reading of: 32 - 32 - 32 or all the pressures are the same, that indicates that the filters may have been taken out of the system or that they are damaged and all the water is flowing through them not being filtered. 

3.  LWW Project # 276/Unit #186 pressure gauges read:  18 - 19 - 19.  This one looks like the 0.5 micron filter cartridge is missing because G-2 equals G-3.   I would say that the 5 micron filter might be out also. 

4.  LWW Project #375/Unit #255 pressure gauges read:  30 - 20 - 10.  This system was installed in November 2008, so it is probably time to change both the 5 micron and 0.5 micron filters.   If G-3 on this system is after the 0.5 micron filter, the pressure will decrease as the filter plugs.  If the G-3 pressure falls below 10 psi, the water flowing through the venturi will not get enough ozone to kill the bacteria.  It is then time to change the 0.5 micron filter.  

 5.  LWW Project #265/Unit #205 pressure gauges read:  36 - 26 - 14.  The 12 psi difference between G-2 and G-3 is another indication that the 0.5 micron filter should be changed.  This system was installed in April 2008, so it is past time to change the filters.