Estimate the right RED RO system
for your foodservice application.
Enter your source-water quality, daily demand, and target delivered-water quality to generate a preliminary RED RO system recommendation. The tool derives the permeate-to-bypass blend the Dynamic Blend Valve would run to hit your target, so you do not have to guess the ratio. A starting point for a spec, subject to engineering review, not a generic catalog guess. Free, no email required.
EC is the working number. If you only have a TDS reading, switch the unit and we convert it for you.
Coffee, espresso, and beverage applications are usually the reason a target delivered-water quality matters; ice and steam applications more often size on flow and scale control.
This is daily volume (GPD), not a flow rate. For simultaneous peak demand in GPM across your equipment, run the Peak-Flow Gut-Check tool.
Default EC 120 µS/cm is the top of the RED's documented standard-output band (EC 70 to 120 µS/cm); site commissioning often targets the low end of that band on purpose. See "How this estimate is calculated" below for how this compares to the Specialty Coffee Association's recommended water range. Adjust the target for your site.
Engineering use only: RO element rejection
Membrane rejection varies with water conditions, temperature, membrane age, and operating conditions. Aquamor engineering sets this value for a real order; change it here only if you are confirming a specific element's rated performance.
Enter your feed water quality, required flow, and target quality above, your recommended RED RO system and derived blend will appear here.
The RED RO family (confirmed): four units (1,000 / 2,000 / 3,000 / 4,000 GPD) sharing a similar system design. The 2,000 GPD unit is the verified anchor (Aquamor RED System Sell Sheet spec table: 2,000 GPD / 1.4 GPM permeate, 95% TDS rejection, one 4×40 spiral-wound RO element).
The target quality, and where it comes from: the RED System is commissioned to a target delivered water quality, not a fixed volumetric blend. Its Dynamic Blend Valve mixes RO permeate with a bypass stream until the delivered water hits that target. The Aquamor RED System Sell Sheet states the standard-output target as EC 70 to 120 µS/cm. This tool defaults the target to EC 120 µS/cm, the top of that documented band, and lets you adjust it. EC (electrical conductivity, in µS/cm) is the working number throughout; a TDS equivalent is shown only as a rough, meter-dependent reference.
Specialty Coffee Association (SCA) water specifications: the SCA Gold Cup Standard sets a target TDS of 150 ppm, with 75 to 250 ppm as its acceptable range. The RED's EC 70 to 120 µS/cm band converts, at this tool's own EC-to-TDS factors, to roughly 35 to 80 ppm TDS, mostly at or below the low end of the SCA's acceptable range. The RED design targets the low end of its band on purpose: feed-water quality varies over time, and the carbon and scale-media filters that are also part of the RED system add some TDS back, bringing the delivered water closer to the SCA range as it reaches the point of use. Treat the RED blend as designed toward, and adjustable toward, the SCA recommended range, not as a claim that every delivered result sits inside 75 to 250 ppm TDS. Confirm the commissioned target with Aquamor engineering when SCA compliance is the deciding factor.
How the blend is derived (not guessed): given your feed EC, the RO element's rejection sets permeate EC (permeate EC = feed EC times one minus rejection). A simple mass balance on conductivity then solves for the permeate-to-bypass split that lands on your target: permeate fraction = (feed EC minus target EC) divided by (feed EC minus permeate EC). The result is shown as an output, the blend the valve would run, never as a number you have to supply.
EC and TDS: conductivity meters and TDS meters do not read the same number, and no single conversion is exact. It depends on the water's mineral makeup and how the meter was calibrated. Aquamor works in EC because it is the direct, unambiguous measurement. Where this tool shows TDS, it uses a NaCl-scale approximation (EC times 0.5), the same default the cartridge tools use; a KCl-calibrated meter would use about 0.67. Treat every TDS figure here as approximate.
Recovery basis: the calculator assumes a fixed 60% RO recovery, the rate Aquamor ships RO systems at and the value used in Aquamor Engineering's own sizing workbook (Red Flow Calculator, 2026-07-22). Recovery is not adjustable on this page and is not derived from your feed water; if a site's actual recovery needs to be confirmed for a real order, Aquamor engineering does that during design.
What remains an estimate: the exact commissioned target for a given site is a field-set value Aquamor engineering confirms, the EC 120 default is a documented starting point, not a per-site guarantee. This tool also does not model membrane flux decline, temperature correction, fouling or scaling, or concentrate staging.
On peak-demand shortfalls: if your required delivered flow needs more RO permeate than even the largest family unit provides at the derived blend, that shows up here as a shift toward more RO-stage bypass blend in the mix at peak times: RO units bypass only the RO stage under peak demand, they do not fail to deliver water.
What to do next: use this as a starting point. Confirm any real order against Aquamor engineering, who can run the actual design against your feed water analysis, temperature, site conditions, and the actual commissioned target.