I am looking for a pressure transducer/gauge that will replace either the actual gauge on my pool filter or the whole assembly. Operating PSI is 5-50 normal is 5-20 and need .5-1psi sensitivity. Any suggestions? Of course needs to be waterproof/capable and preferably be cost conscious (I.e BOM friendly).
I don’t know the exact fitting but I believe it is 1/4 male npt. Or if needed the whole housing can be replaced but would then need to add a solenoid for air release.
Gauge (mine has the fitting on the back but close enough)
http://www.poolweb.com/Home/Other-Product/Pressure-Gauge_4?gclid=CjwKEAjwzdGxBRC3rPWZq83FzyUSJAB9IC5ig5FNlyIkSHU07ZemC3OqvQSNULlwKhq-ySX2hoVWehoCMAPw_wcB
Gauge housing/adaptor to main filter assembly
http://www.poolweb.com/Home/Other-Product/AIR-RELIEF-ASSEMBLY?gclid=CjwKEAjwzdGxBRC3rPWZq83FzyUSJAB9IC5iNgvC4Oy0upm_bz1tjszZCXmTCZCxZlggASS1tYJTzRoCyFrw_wcB
This sounds interesting, i have been thinking of doing the same to my pool, so i can see if the pump is running and alert if the filter needs back flushing. My filter sits at 50PSI after a back flush and goes up to 100PSI before I do anything about it
Stay tuned. I have lots planned. Do you have an automation system today? Single speed or variable speed pump? Pool/spa combo? Any booster/blower pumps?
Filter pressure is the number 1 indicator of filter efficiency/health. 
its a salt pool so there is a chlorinator, that has a no flow indication and low salt indication on it, the chlorinator controls the pump, the pump has 3 speed settings, so it starts at full speed for 5 minutes to prime, and then goes to the selected speed to save power. it runs for 4 hours a day in winter and 8 to 10 hours a day in summer
I am planning to add a small booster pump for solar heating later on when i have some spare cash!