[Andrew44]

I've been told that my water pressue from outside tap is about 40 psi.  However, when I run RO the readings are amazingly low.  inlet to filters 10 and outlet no reading !!  I've run a simple test and can fill 1 lt in 5 secs from out side tap.  Through garden hose and just before the filter it takes same time to fill 1ltr so there appears to be no lose in pressue from tap to end of hose.

Does anyone know what th water pressue would be to fill 1 ltr in 5 secs or 1 gallon in 23 secs??  It does n't seem low at source and even at end of hose but pressue way down according to gages.

Any ideas??

[Helen]

Inlet pressure of 40 psi is a bit low for an RO system (fit a booster pump).
Pressure after filters will be really low, that is what the filters do. If you had the same pressure of water production (after filters) as you have at source tap then you'd have the system we would all want
The actual test for if the system is correct is to measure the amount of pure water produced against the amount of waste water. You can use a stop watch for this to see how long it takes to fill up to 200ml. All systems vary on their ratios of product to waste but you should be looking for somewhere in the region of 60/40