For those that are going to dive in here, let me emphasize that the best part of this whole set up is never having to worry about your water and what's going on inside your machine. No worries about filter performance or aging, or bypass %, or the income water changing over the seasons.

Thank you to everyone here for educating me on some water basics. Having departed awesome CO water and found hello crappy AZ water. I packed up my espresso machine and roaster back in March 2019. Scottsdale water has a ton of chlorides. Since there was no convenient place in the new house for the espresso machine near the kitchen RO with remineralizer, I transitioned to an espresso cart. This setup has been used by quite a few others now.

The set up is: Holding tank>shut off>check valve>pump>accumulation tank>shut off>pressure regulator>espresso machine



EDIT - JANUARY 2023 - Have now used this flawlessly for nearly 4 YEARS and highly recommend it. You can either use RO water without reminerialization or distilled water. This system is particularly great if you have high chlorides (different than chlorine). If you use an RO to feed your tank, you will want to get a flow measurement device to know how much buffer and hardness stock you want to add. I have collected my learnings on this forum in a document called "Coffee Water Made Easy for a Non-Chemist" and am happy to share them if you PM me with an email address. In Jan 2023 I decided to put the Aquatec on a smart timer. Don't know why I didn't do this earlier but now for sure it doesn't go off in the night and often it cycles first thing after being turned on which means I know I have great pressure for the day.

NOTE: I originally rejected Flojet as a pump choice. After post 96; another 5000 series failure after 14 months, I continue to not recommend them. One of their products only provides 40psi. ASLO if you are doing line pressure pre infusion, you might consider a high end pressure gauge such as a Swagelok. AND, I am not sure that a variable pressure pump makes sense if you use an accumulator tank

Some insight into this system is said well in post 103 by my friend and mentor Dan.

I have owned 3 different brands of diaphragm type pumps for various water delivery systems over the years and although they all can be construed as "noisy" the Aquatec isn't quite as loud (relative); it seems smoother in its vibration pattern (kinda of like the difference between a stroker motor and higher revving motor with less cam lift). Use vibration isolating pads between the mounting surface and the pump's feet and for best sound isolation, construct a box lined with acoustic foam panels, sound deadening material, over the pump itself.

And to minimize vibration transfer from the inlet and outlet side of the pump, if you can, incorporate a short section of softer durometer/more flexible water line if you are using more rigid water tubing within the system. This will absorb some of the vibration that would otherwise be transmitted throughout the system. This is more of a concern, say in an RV , where larger diameter PEX type water lines are used. FWIW/FYI, I didn't bother with deploying this technique in my espresso machine water delivery system.

This box still needs some ventilation, however the pump doesn't run that long in my system (I'm using a 2-gallon SS Shurflo accumulator; bigger is better to minimize pump cycling and high/low pressure differentials within the water delivery system). Isolating the mounting feet of the accumulator also helps isolate vibration, although less so than isolating the pump.

The accumulator will lengthen the time between pump cycles. You should also note, the water pressure measured at the espresso machine, will have a range: Higher PSI/BAR right after the pump cycles and lower PSI/BAR right before the pump cycles. Most of the pumps have an adjustable pressure switch but when you're shopping pay attention to the minimum & maximum PSI range for pump on/off cycling. The more narrow this range, the smaller the differential between high and low system water pressure (but the more frequent it will cycle). Probably the biggest reason to incorporate an accumulator within your system and to go with the largest capacity you can within the respective space for the system: Less frequent cycling of the pump and more consistent water pressure at the espresso machine.

Regulators, I have found through using water delivery systems for my espresso machines the past 10+ years, are complex beasts all their own. Incorporating a pressure regulator will allow you to set a static water pressure level for the system but the system will still have a pressure range. Here's a link that provides an overview of what they do and what you can expect it to perform for the system.

All in all, even given the limitations I describe above, I prefer this type of water delivery system over a more complex and expensive array of filters, mineral add-backs, etc., from a consistent pressure regulated municipal water supply, that provides the ability & versatility to easily use whatever water I want.

Sorry about some the image sizes.

Here is the final product on the cart. Note the wide mouth on the tank makes filling easy. The waste tank has a handle which makes it easy to carry out to the garden and dump. The cart has LEDs on a timer and this was an early am shot. You will also see in the image a stainless tank which holds my aquarium brushes which are used for cleaning tubes as well as a white Ember Mug recharging saucer.



Holding Tank - 6 gallon rectangular tank. July 2020 edit notes. I find this tank really needs to be refilled with four gallons as the exit point is not at the very bottom of the tank. Four gallons lasts about three weeks for 4-6 espressos a day plus cleaning routines. Note the wide mouth opening makes refilling very easy.



I am considering replacing the tank with this 16 gallon larger one which would fit my space although the opening is only 4" and not 5".

To use the Holding Tank with JG 3/8 tube you will need a reducer bushing of some sort and JG adapter. I chose the following. You might want to base your decision for the reducer on whether you can buy a single (rather than a pack of 10) JG adapter. Note the this link below for the reducer is not the one I got as I didn't know I would need it. Confirm fit first but since its from the same website should work.

Reducer Bushing 3/4" NPT Male x 1/2" NPT Female



John Guest ½ NPTF Straight Adapter 3/8 OD tubing PP011224W 3/8" 1/2"




Check Valve to prevent backflow when refilling tank. [Not sure this is necessary but is nice to have so I don't have to turn the shut off valve]



Pump
Aquatec 5853-7E12-J524 1.7 GPM 60 PSI 3/8 inch JG 120V Delivery/Demand Pump with Cord.



Pump Specs - note the run dry protection.



3.2 Gallon Accumulator - with a John Guest 3/8 adapter on top connects into pump line with a T. You can get a smaller accumulator but it will likely cycle the pump more often.



J Guest Valve for Accumulator



John Guest T - one side to pump and other side to pressure regulator before espresso machine with the T side to the accumulator.



John Guest 3/8 tubing


Shut off valves for 3/8 John Guest Tubing - I recommend you order at least 3 if not 4 of these. Extra ones are useful for cleaning operations.


Pressure regulator - I chose the 0-125 range as sometimes the pump puts you over 60. Turn the screw clockwise to tighten it and increase the pressure, or turn it counterclockwise to decrease the pressure.
Watts 560 pressure regulator


For more precision at more cost consider a Swagelok pressure gauge.

Waste Container



Note this is what I use by OXO to measure my water stock and for refilling. This is excellent as the precision tip lets you drip a little out at a time and since it's stainless you can clean it well and not contaminate your stock.