Reverse Osmosis Systems Reference

Why this reference exists

Reverse osmosis (RO) is the most-installed water purification system in residential. Under-sink RO removes 95-99% of contaminants. Whole-house RO is premium. Service revenue: change visit, recurring every 6-12 months. This is the working framework for sale + install + service.

How RO works

Water passes through:

1. Sediment pre-filter (5-micron): catches dirt + rust
2. Carbon pre-filter: removes chlorine (would damage membrane)
3. RO membrane: semi-permeable membrane allows water but rejects dissolved solids
4. Carbon post-filter (polishing): final taste + odor
5. Optional remineralization: adds back beneficial minerals (some customers prefer mineral water taste)

Result: water with 95-99% of dissolved solids removed.

Waste stream: typically 3-5 gallons wasted per 1 gallon produced (newer systems 1:1 ratio).

RO product categories

Under-sink RO (most common):

• Standard 50-100 GPD (gallons per day)
• system + install
• Storage tank under sink (3-7 gallon)
• Dedicated faucet at sink
• Use for drinking + cooking only

Whole-house RO (premium):

• 500-1,500 GPD systems
• install
• Whole-house filtered
• Wastes more water
• Tankless models available

Tankless RO (newer):

• Direct-flow on demand
• No tank; smaller footprint
• 75-200 GPD continuous
• system + install
• Higher flow rate

Counter-top RO:

• Plug-and-play
• system
• No install required
• Counter footprint
• Limited capacity

For most: under-sink RO at kitchen sink. Whole-house if customer demands or significant water quality issues.

When to recommend RO

Strong fit:

• High TDS (total dissolved solids) > 500 ppm
• High dissolved hardness
• Specific contaminants (lead, nitrates, sodium, sulfate, fluoride concerns)
• Customer-driven (taste + safety + convenience)
• Pregnancy or infant in home
• High-end real estate market

Weak fit:

• Already-soft water with no contaminants
• Customer concerned only about taste (carbon filter cheaper alternative)
• Customer wants minerals (RO strips them; carbon doesn't)
• Customer can't accept waste water (RO wastes 3-5x produced volume)

Pre-install testing

Water test reveals what's actually in water:

• TDS: total dissolved solids in ppm
• Hardness: calcium + magnesium
• Iron + manganese: staining concerns
• Nitrates: well water concern
• Lead: pre-1986 plumbing concern
• Specific organics: chlorinated chemicals

Cost: (customer-paid pass-through).

For known good water + customer driven: RO at kitchen alone fine without full test.

For unknown water + significant decision: full test first.

Installation procedure

Under-sink RO standard install:

Step 1: Customer prep

1. Customer signs scope
2. Verify cold water supply line accessible
3. Drain access (typically under sink)
4. Sink hole for dedicated faucet (drill if needed)

Step 2: Mount system

1. Bracket on cabinet wall
2. Vertical orientation
3. 12-18" from supply tap

Step 3: Connect supply

1. Tap cold water supply line (saddle valve OR T-fitting)
2. Run flexible tubing to system inlet
3. Pressure-tight connection

Step 4: Tank install

1. Vertical orientation in cabinet
2. Connect to system output
3. Air bladder pressurization (typically 5-7 psi when empty; 35-40 psi when full)

Step 5: Drain connection

1. Drain saddle on sink drain pipe (above the trap)
2. Concentrate waste line from system to drain
3. Check valve to prevent backflow

Step 6: Dedicated faucet

1. Customer-chosen faucet (chrome, brushed nickel, etc.)
2. Drill hole in countertop if not pre-drilled
3. Faucet mounts on counter
4. Tubing from system to faucet underneath

Step 7: Initial fill + flush

1. Open supply valve
2. System fills tank (1-2 hours)
3. Flush first tank fully (discharge through faucet)
4. Refill + use

Step 8: Customer briefing

1. Filter change schedule
2. Dedicated faucet operation
3. Annual maintenance schedule
4. Warranty documentation

Service contract opportunity

RO customers benefit from regular service:

• Sediment pre-filter: every 6-12 months
• Carbon pre-filter: every 6-12 months
• RO membrane: every 2-5 years
• Post-filter: every 6-12 months
• Tank pressure check + recharge
• Annual visit:

100 customers = K-30K recurring revenue annually.

Filter quality

Filter performance varies by brand:

Tier 1 (premium):

• iSpring, Aquasana, AO Smith
• 5-stage minimum
• Quality membranes (Filmtec, Dow)
• systems

Tier 2 (mid):

• Generic 5-stage systems
• Quality components
• systems

Tier 3 (budget):

• Off-brand
• Component quality variable
• systems

For pro install: tier 1 or 2. Budget systems fail or perform poorly.

Common pitfalls

• Wrong system size: too small for household consumption
• Bad water quality input: high sediment damages membrane fast
• No pre-filter: same as above
• Forgot drain saddle: drainage issue or leak
• Tank pressurization wrong: water flow restricted
• Membrane expired: customer didn't replace at 3-5 years
• No customer education: filters not changed; performance degrades
• Plumbing leak post-install: shutoff valve location matters

Customer questions + answers

"Will RO remove minerals?"

"Yes - 95-99% of dissolved solids including minerals. Calcium, magnesium, fluoride all removed. Some customers prefer remineralized RO (adds minerals back); others prefer mineral-free."

"How much water does it waste?"

"Traditional systems waste 3-5 gallons per gallon produced. Modern tankless systems: 1:1 or 2:1 ratio. Better for water conservation."

"How do I know when to change filters?"

"Sediment + carbon: every 6-12 months. Membrane: every 2-5 years based on water quality. We provide a maintenance schedule + reminder calls."

"What about waste water - can I redirect to irrigation?"

"Some systems allow redirection; check local code (some jurisdictions require RO waste to drain, not landscape due to high TDS in reject stream)."

"Does RO water taste different?"

"Yes - cleaner, less mineral taste. Some customers love it; others prefer mineralized water. Try before commit."

When NOT to install RO

Wrong fit: already-pure soft water (carbon sufficient), high water-waste intolerance, no drain access for whole-house, customer wanting mineral taste. Honest "not right for you" earns trust.

Service tips

Maintenance visits: customer consumption sized correctly, TDS in/out (membrane health), pre-filter inspection, membrane visual (slime/damage), tank pressure check, demonstrate clean water.

Customer talking points

For RO sale:

References

• NSF/ANSI Standard 58 (RO Drinking Water)
• EPA Safe Drinking Water Act
• WQA (Water Quality Association) certifications
• Manufacturer manuals (iSpring, Aquasana, AO Smith, Pelican)
• Manuall internal: Water Quality and Treatment Reference, Well Water Systems Reference