Under-Sink RO Explained
Under-sink reverse osmosis is the standard choice for 90% of Orlando homeowners. The entire system fits neatly under your kitchen sink, with a dedicated faucet installed on your countertop or sink deck. Here is exactly what it covers:
- Coverage: Drinking water and cooking water at one faucet (typically the kitchen sink)
- Capacity: 50-100 gallons per day production, 3-4 gallon storage tank
- Installation time: 2-3 hours
- Space needed: 20 inches vertical clearance under sink
- Wastewater: 3-4 gallons per gallon produced (1-1.5:1 with permeate pump)
For most Orlando families, this is all you need. Drinking and cooking water represents about 5% of total household water usage. An under-sink RO delivers the purest water where it matters most — your glass and your cooking pot — at a fraction of the cost of a whole-house system.
Whole-House RO Explained
Whole-house RO treats every drop of water entering your home — drinking water, shower water, dishwashing water, laundry water, and irrigation water. This is a major installation that requires significant space, plumbing modifications, and ongoing maintenance:
- Coverage: All water entering the home — every faucet, shower, appliance, and outdoor spigot
- Capacity: 750-2,000+ gallons per day production, 50-100 gallon storage tank
- Installation time: 4-8 hours
- Space needed: 2-4 square feet floor space, 8-10 feet vertical clearance
- Wastewater: 3-5 gallons per gallon produced (massive water waste)
- Electrical: Requires dedicated 110V circuit for automated controls
- Plumbing permits: Required in Orlando for whole-house installations ($50-150)
Whole-house RO is only recommended for homes with severe water quality issues throughout the entire supply — high arsenic in well water, industrial contamination in municipal supply, or other system-wide problems. For typical Orlando municipal water, a whole-house RO is overkill.
Cost Comparison
The cost difference between under-sink and whole-house RO is significant:
| Cost Factor | Under-Sink RO | Whole-House RO |
|---|---|---|
| System cost | $300-650 | $1,500-5,000 |
| Installation | $200-400 | $1,500-3,000 |
| Annual maintenance | $100-250 | $300-600 |
| Wastewater cost/year | $30-60 | $900-1,800 |
| Total 5-year cost | $800-2,000 | $12,500-25,000 |
Notice the 5-year total — whole-house RO costs 6-12x more than under-sink RO. For the vast majority of Orlando homeowners, that investment does not provide proportional value since under-sink RO already delivers pure drinking water at the kitchen faucet.
Which Is Right for Your Home?
Choose under-sink RO if:
- You want pure drinking and cooking water
- Your water quality is acceptable for bathing, laundry, and cleaning
- Your budget is $800-1,500 installed
- You want to minimize wastewater
- You do not want to deal with permits and major plumbing work
Choose whole-house RO if:
- Your water test shows elevated contaminants (arsenic, lead, PFAS) in all water entering the home
- You have a private well with documented contamination
- You want RO water for showering, bathing children, and laundry
- Your budget is $3,000-8,000 installed plus $300-600/year in maintenance
- You have adequate space in a garage or utility room
Bottom line: Under-sink RO ($800-1,500 installed) is the right choice for 90% of Orlando homes, providing pure drinking and cooking water at the kitchen faucet. Whole-house RO ($3,000-8,000 installed) is only necessary for homes with severe, system-wide water contamination. Most Orlando homeowners save $2,000-5,000 by choosing under-sink RO plus a water softener, which together address both drinking water quality and hard water issues.
Orlando-Specific Considerations
For Orlando homeowners specifically, here are the local factors that influence your RO system choice:
Building age: Orlando has a wide range of housing stock. Newer homes (built 2010+) use PEX or PVC plumbing, which is not affected by RO water pH. Older homes (built before 1990) may have copper plumbing that benefits from remineralization.
Water pressure: Orlando's municipal water pressure (40-80 PSI) is ideal for RO. If your home has a booster pump for your water softener, ensure the pressure does not exceed 80 PSI — this can damage the RO membrane.
HOA requirements: Some Orlando HOAs have restrictions on exterior plumbing modifications. If you are considering a whole-house RO system, check your HOA rules before proceeding. Under-sink RO systems are typically exempt from HOA restrictions.
Insurance: Some Orlando homeowners insurance policies offer discounts for installed water treatment systems. Check with your insurer — an RO system may reduce your premium by 2-5%.
Bottom line: For 90% of Orlando homes, an under-sink RO system ($800-1,500 installed) is the right choice, providing pure drinking water at the kitchen faucet. Whole-house RO ($3,000-8,000) is only necessary for homes with severe, system-wide water contamination. Most Orlando homeowners save $2,000-5,000 by choosing under-sink RO plus a water softener, which together address both drinking water quality and hard water issues. Get a free water test to determine your home's exact needs.
The Ideal Orlando Water Setup
For most Orlando homes, the ideal water treatment setup includes three components: a whole-house sediment pre-filter ($100-200) catches sand and rust from municipal supply, a water softener ($1,500-3,000 installed) removes hardness minerals to prevent scale buildup on pipes and appliances, and an under-sink RO system ($800-1,500 installed) removes dissolved contaminants from drinking water. Total cost is $2,400-5,500. This setup protects your plumbing, prevents scale buildup, and delivers pure drinking water — the complete solution for most Orlando homes.
Can I install both under-sink and whole-house RO?
Yes, many Orlando homes install both — an under-sink RO for drinking/cooking water (most common) plus a whole-house pre-filter for sediment and chlorine protection. A whole-house RO system is only added if testing shows contaminants throughout the entire water supply. Most homes only need under-sink RO.
How much space does a whole-house RO system need?
A whole-house RO system requires 2-4 square feet of floor space and 8-10 feet of vertical clearance. Typical installation locations are the garage, utility room, or a dedicated equipment room. The system includes multiple tanks (pre-filtration, RO membrane, remineralization) and a large storage tank.
Is whole-house RO worth the cost for most Orlando homes?
For 90% of Orlando homes, whole-house RO is NOT worth the cost. Under-sink RO ($800-1,500) handles drinking and cooking water perfectly. Whole-house RO ($3,000-8,000) treats all water entering the home but generates 3-5x more wastewater and requires $300-600/year in maintenance. Only choose whole-house RO if testing confirms contaminants throughout your entire water supply.
What is the best RO system for a large Orlando family?
For large families (5+ people), an under-sink RO with a 100 GPD membrane and a 7-10 gallon storage tank is ideal. This provides instant RO water without waiting for the tank to refill. The extra tank capacity ensures the family never runs out of pure water even during peak usage. A whole-house system is unnecessary unless water quality testing shows system-wide contamination.
Do I need a whole-house RO if I already have a water softener?
A water softener and RO system serve completely different purposes. A water softener removes hardness minerals (calcium, magnesium) to prevent scale buildup on pipes and appliances. An RO system removes dissolved contaminants (lead, fluoride, PFAS, arsenic) from drinking water. Most Orlando homes have both — a water softener for whole-home protection and an under-sink RO for pure drinking water.