Ro/di pressure gauge

[r0bin]

Did you need one of these on the RO unit you purchase and why? Also how does an automatic shut off work if you are hooking it up to a kitchen sink?

 

[AZDesertRat]

A pressure gauge is a tool that helps you determine if your filters are plugged and when to change them. I prefer two gauges myself, one on the incoming or tap water side and one after the final carbon/before the membrane so I can see at a glance the pressure drop across the filter array. Its also used to correctly judge output and in setting the waste ratio.
An autoshutoff is not necessary if you plan on using your RO as a portable all the time. I would still buy a unit with one already installed if you are buying new though since it will be cheaper in the beginning plus it will already be plumbed correctly if you ever decide to install the RO permanent which is a lot nicer. Heck use it for drinking water and ice maker too, it makes the cost much easier to justify.