Sources: AWWA Membrane Technology Manual • AMPAC USA • Seven Seas Water Group • Aguato membrane selection framework • EPA • Updated June 2026
Commercial RO systems force pressurized water through a semi-permeable membrane, rejecting dissolved solids, heavy metals, nitrates, PFAS, and ionic contaminants. A well-designed commercial system achieves 90–99% TDS removal — essential for applications where product quality, equipment longevity, or regulatory compliance depends on low-TDS water.
Contents
| Application | Typical Capacity | Key Driver | CWL Reviews |
|---|---|---|---|
| Car detailing / window washing | 500–2,000 GPD | Spot-free rinse water | Falcon FALM Series |
| Restaurant / food service | 1,000–4,000 GPD | Ice, steam, beverage quality | Raptor Lite |
| Light manufacturing / greenhouse | 1,500–8,000 GPD | Process water quality | Falcon FALM-2000 |
| Boiler feed water | 2,000–20,000 GPD | Scale prevention, conductivity | Defender HD |
| Healthcare / dialysis | 3,000–15,000 GPD | AAMI TIR34 compliance | Healthcare guide |
| Large commercial / industrial | 8,000–16,000+ GPD | Volume, uptime, regulatory | Patriot XL |
Reverse osmosis and ultrafiltration are not interchangeable — they solve fundamentally different water quality problems. Applying RO to a problem that UF could solve at half the cost is the most common over-specification mistake. Skipping RO where TDS is the real issue is the other.
| Factor | Reverse Osmosis | Ultrafiltration |
|---|---|---|
| Removes dissolved salts/TDS | Yes — 90–99% | No |
| Removes bacteria & viruses | Yes | Yes (bacteria); viruses depend on pore size |
| Removes PFAS | Yes | No |
| Operating pressure | 150–600 PSI | 15–75 PSI |
| Energy consumption | 0.2–0.5 kWh/gal (brackish) | ~70% lower than RO |
| Water recovery rate | 50–85% | 90–95% |
| Capital cost | Higher (>$5,000 commercial) | Lower (~50% of RO) |
| Choose when… | TDS, hardness, PFAS, or ionic removal is required | Suspended solids, turbidity, or microbial removal only; TDS not a concern |
Four membrane technologies span the range from coarse particle removal to near-molecular separation. Filtration precision order: RO > NF > UF > MF. Choose the least aggressive technology that meets your compliance target.
MF — Microfiltration
Pore size: 0.1–10 micron
Removes: sediment, suspended solids, protozoa
Does NOT remove: bacteria, viruses, dissolved solids
UF — Ultrafiltration
Pore size: 0.01–0.1 micron
Removes: bacteria, most viruses, colloids, proteins
Does NOT remove: dissolved salts, TDS, PFAS
NF — Nanofiltration
Pore size: 0.001–0.01 micron
Removes: hardness, some divalent ions, color, pesticides
Partial TDS removal; monovalent ions (Na, Cl) largely pass through
RO — Reverse Osmosis
Pore size: 0.0001 micron
Removes: dissolved salts, TDS, PFAS, heavy metals, nitrates, virtually all contaminants >0.0001 micron
Understanding these specifications prevents both undersized systems (production bottlenecks) and oversized ones (unnecessary capital spend).
| Specification | What It Means | Engineering Context |
|---|---|---|
| Rated capacity (GPD) | Permeate output at standard test conditions | Tested at 77°F, 150 PSI, 500 ppm TDS feed. Cold feed water reduces output significantly — apply temperature correction factor (TCF). |
| Recovery rate (%) | Permeate ÷ feed water × 100 | Commercial systems: 50–85%. Higher recovery = less concentrate waste but more membrane scaling risk. Concentrate recycle can push recovery to 75%+ on some systems. |
| Salt rejection (%) | TDS removed as % of feed TDS | 98–99.5% for new membranes. Monitor monthly — membrane replacement is indicated when rejection drops below 90%. |
| Feed pressure (PSI) | Pressure required at membrane inlet | Brackish water: 150–300 PSI. Higher TDS or higher recovery requires higher pressure. Always verify minimum feed pressure from supply line before purchasing. |
| Membrane type | Polyamide thin-film composite (TFC) is standard | TFC membranes have zero chlorine tolerance — dechlorination pre-treatment is mandatory on any chlorinated supply. Cellulose acetate (CA) tolerates low chlorine but has narrower pH range and lower rejection. |
| Flux rate (GFD) | Gallons per square foot of membrane per day | Operating above recommended flux accelerates membrane fouling. Commercial systems typically operate at 10–15 GFD; lower is better for longevity. |
| Temperature correction | TCF multiplier for cold water | At 50°F, a system produces ~58% of its rated 77°F output. Size for actual cold-season feed water temperature, not the rated spec. |
Start with measured daily water consumption — not an estimate. Note peak demand periods and seasonal variation. Add a minimum 25% safety margin. This real-world data should always drive the final specification; skipping this step leads to undersized systems and constant production bottlenecks.
| Application Type | Typical Daily Demand | Sizing Notes |
|---|---|---|
| Car detailing (1–2 operators) | 200–500 GPD | Peak demand at rinse stages; storage tank bridges production gaps |
| Restaurant (full-service, 100-seat) | 1,000–2,500 GPD | Ice machine + steam table + beverage; size for peak service period |
| Small greenhouse / nursery | 1,500–5,000 GPD | Seasonal variation significant; summer demand may be 3× winter |
| Light manufacturing process water | 2,000–10,000 GPD | Production schedule drives demand; continuous operation vs batch |
| Hotel / hospitality (100 rooms) | 3,000–8,000 GPD | Laundry and kitchen dominate; occupancy rate affects daily total |
| Industrial boiler feed | 5,000–50,000+ GPD | Steam load and blowdown rate determine feed water requirement; consult boiler engineer |
Pre-treatment is the single most important factor in membrane longevity. The membrane is the most expensive component in a commercial RO system — pre-treatment exists entirely to protect it. Skipping or under-specifying pre-treatment voids warranties and causes systems to underperform within months of installation.
| Pre-Treatment Stage | What It Prevents | When Required |
|---|---|---|
| Carbon filtration (dechlorination) | Irreversible TFC membrane destruction | Mandatory on ALL chlorinated municipal supplies |
| Sediment pre-filter (5 micron) | Membrane fouling, pump damage | Always required — replace when differential pressure exceeds 10 PSI |
| Softening or anti-scalant | Calcium/magnesium scaling on membrane surface | Required when hardness >7 GPG; anti-scalant injection extends warranty on some systems |
| Iron/manganese pre-treatment | Rapid membrane fouling, colored permeate | Required when Fe >0.1 ppm or Mn >0.05 ppm |
| pH adjustment | CaCO⊂3; scaling at high pH; membrane degradation at extremes | Required when feed pH >8.5 or <4.0; check membrane pH limits (TFC: 3–11) |
The purchase price of a commercial RO system is typically 20–35% of the 5-year total cost of ownership. Operating and maintenance costs dominate. Systems with inadequate pre-treatment frequently require membrane replacement every 12–18 months instead of every 3–5 years — tripling the effective membrane cost.
The AWWA Membrane Technology manual and commercial system engineers consistently recommend a full water analysis panel — not just TDS — before specifying any membrane system. The analysis drives pre-treatment selection, recovery rate targets, anti-scalant choice, and system sizing.
Minimum analysis panel before specifying a commercial RO system:
US Water Systems Falcon Commercial RO — FALM-500 through FALM-2000
500–2,000 GPD • 75% recovery • 110V single-phase • 98.5% rejection
US Water Systems Defender HD
2,000–16,000 GPD • Brackish RO • $7,195
US Water Systems Patriot XL
8,000–16,000 GPD • Turnkey skid • UV + pre-treatment integrated
Raptor Lite — Food Service RO
3,290 GPD • Restaurant and food service applications