DIY Custom TDS Water Filtration System For Perfect Coffee Water

Here at Telemetry Coffee Roasters I just put the last touches on our new water filtration system. The city water coming in is 26 grains of hardness with a PH close to 8. Getting the water down to optimal coffee levels was a fun project. With two 20 gallon storage tanks I have plenty of water filling my 30 gallon cold brew tank. Also there us a 3/4 line running from the tanks to the hose so we have a lot of flow. All together the whole project was a little over 00 and about 3 days of installation.

1. We are in an old part of town and there is lots of sediment in the pipes. Whenever water is shutoff to the town or the hydrants are flushed, sediment comes in the building. A 30 micron pleated filter removes any large sediment and helps protect the softener.

2. With TDS coming in just over 400 PPM and most of that being calcium a regular RO system would be susceptible to early membrane fouling. I put in an softener but I am using the service valve on the back to blend in soft and hard water. My goal is about half softened. If this valve ends up not being precise enough I may plumb in a “stop and waste” valve.

3. The RO system was a system I found on ebay for a decent deal. It has a pump and a reverse valve to flush the membranes when not in use. The pump helps increase the osmotic pressure differential, this both speeds up the system and increases the total GPD. The advertised a 1:1 rejection ration (for ever 1 gallon of finished water 1 gallon is wasted) but it is probably lower given my low (50 psi) inlet water pressure. When thy system becomes it reverse directing and sends RO’d water back through the membranes, this reduces the contact time with really hard water and helps extend the life of the membranes.

4. I have gauges pressure gauges on the inlet, post pump and post membranes sides. Once I get some baseline reading this should help determine when filters or membranes need replaced.

5. On top is an inline TDS meter. This shows how well my membranes are working and how my blending is doing. Next to it is a stainless steel needle valve where none RO’d water is blended with the RO’s water. The inlet Tee is after the opening solenoid valve but before the pump. The outlet is after the membranes but 6 inches from the outlet TDS meter. There is currently not a lot of play in the valve. I installed a small flow restrictor and it helped, but I plan on experimenting with different flow restrictions to see if I can get more precise dossing with the valve.

6. The 1/4″ outlet quickly changes to 3/4″ CPVC. There it heads for two 20 gallon RO storage tanks. I should get about 14 gallons of storage on each. The 3/4″ lines will give me adequate flow rates for the coffee maker, espresso machine and 30 gallon cold brew pot.

7. After the storage tanks the water goes to an active carbon filter to remove and taste from the storage tanks. Then one line goes to a hose bib we use fore making cold brew and the other line goes into the shop for the coffee maker and espresso machine. I may add another line in the future for a drinking fountain and bottle fill station. Bad water is a problem for most of my customers, If I want my coffee to taste good in there equipment then I may need to either educate them or provide them with coffee water to take home.

Here is a list of all the equipment I used and where I got it from. If anyone has specific questions on how I set this up and want some advice for a similar setup just shoot me a PM.

* RO System 0

* Storage Tank 9 each

* Water Softener 0

* Inline TDS Meter

* Pressure Gauges each

* 20″x2.5″ Filter Cartrige each

* Stainless Steel Needle Valve (It was when I got it, showing for now)

* Filter Brackets ~ each (The ones I ordered didn’t fit. I drilled new holes in them. Better off looking for ones that match.)

* Various plumbing parts from Lowe’s was about 0



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