The first step towards reducing water consumption, is to know how much you are using in the first place. See Fresh Water Stewardship. My water system is simple in the Squatch; it has a 66 gallon tank, a 12VDC pressure pump, an accumulator tank, and now, two mechanical water meters. I found these meters on Ebay. They’re from a company called “B Meter”. The GSD5 product was one of the cheaper models, having no pulse output for an electronic counter. Here’s a link to the company website: http://www.bmeters.com/en/single-jet-water-meter.htm
The dial is magnetically coupled to the paddle wheel in the brass body, such that there is no water contact. I’m quite pleased with them. The dial can be rotated 360 degrees for easy reading whether the meter is installed in the vertical or horizontal position. The only trouble I had with them was adapting to the 1/2″ threaded male fitting. I immediately noticed the threads were not tapered and were instead straight. Without placing an O-ring or other seal in the bottom of the plastic “push-fit” fittings I coupled to them, they would not seal under pressure. I found that the swivel type plastic fittings with a cone shaped rubber seal in the center worked, but I only had one of them, and no local plumbing supply or hardware store were any help in procuring more. In fact, most people looked at me like I was stupid when I said the threads were straight and not tapered. Oh well. The O-rings seal fine. In the future I’ll get the correct fittings.
One meter is installed directly after the accumulator tank, to monitor total water consumption, and the other meter is installed after the water heater, to monitor hot water consumption. The difference of course, is the cold water consumption alone.
They read in cubic meters, or 1000 liters, with a rollover dial in cubic meters and a series of circular dials reading 100L, 10L, 1L, and 10 deciliters. So, a reading of 0.1209 would be 120.9 liters. Having a digital readout would be nice since peering back under the kitchen sink to take readings is kind of a pain in the ass, but this doesn’t require any electricity and is much simpler. It just requires that I take the readings manually when determining water consumption for a particular task like showering, or when collecting daily consumption values.
I haven’t yet tested the meters for accuracy other than filling a large kitchen measuring cup. Better testing equipment needs to be acquired. Perhaps measure by mass. One thing is clear; although the meter registers water flow at all but the lowest flow rates, it certainly loses accuracy at a water trickle.