In the world of under-sink water filtration, few systems are as renowned and widely discussed RWU UAR . This reverse osmosis (RO) unit has become a benchmark for homeowners seeking to eliminate up to 99% of contaminants from their drinking water. But what exactly is it, how does it work, and is it the right choice for your home?
This guide will break down everything you need to know about the RWU UAR, from its core technology and performance to key calculations for understanding its efficiency.
What is the RWU UAR 1000?
The RWU UAR 1000 is a high-capacity, 5-stage reverse osmosis water filtration system designed for point-of-use installation, typically under a kitchen sink. The “UAR” designation often refers to its “Ultra-Access Reverse” design, which emphasizes easy filter changes and maintenance. The “1000” signifies its large storage tank capacity, holding approximately 1000 ounces (approximately 3.1 US gallons or 11.8 liters) of purified water.
This system is engineered to remove a vast array of impurities, including:
- Dissolved salts and metals (Lead, Arsenic, Chromium, Sodium)
- Chlorine, Chloramine, and other chemicals
- Pesticides, herbicides, and pharmaceutical residues
- Bacteria, viruses, and cysts (like Giardia and Cryptosporidium)
- Total Dissolved Solids (TDS)
The 5-Stage Filtration Process Explained
The effectiveness of the RWU UAR 1000 lies in its multi-stage filtration process:
- Stage 1: Sediment Filter. A 5-micron polypropylene filter removes dirt, rust, sand, and other suspended particles, protecting the subsequent filters from clogging.
- Stage 2: Granular Activated Carbon (GAC) Filter. This filter absorbs chlorine, chloramines, volatile organic compounds (VOCs), and other chemicals that affect taste, odor, and can damage the delicate RO membrane.
- Stage 3: Carbon Block Filter. A finer, compressed carbon block provides a second layer of chemical filtration, ensuring the water entering the RO membrane is as clean as possible.
- Stage 4: Reverse Osmosis Membrane. The heart of the system. This thin-film composite (TFC) membrane features extremely tiny pores (around 0.0001 microns). It uses household water pressure to force water molecules through, rejecting up to 99% of all dissolved solids and contaminants, which are then flushed down the drain.
- Stage 5: Inline Post-Carbon Filter. This final “polishing” filter removes any remaining tastes or odors that may have been picked up from the pressurized storage tank, ensuring every glass of water is crisp and clean.
Key Calculation: Understanding Wastewater Ratio
A critical aspect of any RO system is its efficiency, often measured by its wastewater ratio (also called the drain ratio or rejection rate). This is the ratio of purified water produced to wastewater sent to the drain.
The Formula:Wastewater Ratio = Gallons of Wastewater / Gallons of Product Water
Modern RO systems like the RWU UAR 1000 are far more efficient than older models. While old systems had ratios as high as 1:4 or 1:5 (meaning 4-5 gallons wasted for every 1 gallon purified), the UAR 1000 typically operates at a much more efficient 1:1 to 1.5:1 ratio.
Calculation Example:
Let’s assume your RWU UAR 1000 produces 3 gallons of purified water and sends 4.5 gallons to the drain during a single filtration cycle.
Wastewater Ratio = 4.5 gallons wastewater / 3 gallons product water = 1.5
This gives a ratio of 1.5:1. For every 1 gallon of clean water you get, 1.5 gallons are used to flush contaminants from the membrane.
Factors affecting this ratio include: incoming water pressure, water temperature, and Total Dissolved Solids (TDS) level.
(FAQs)
Q1: How often do I need to change the filters on the RWU UAR 1000?
A: Filter change frequency depends on your water quality and usage.
- Prefilters (Stages 1, 2, 3): Every 6-9 months.
- RO Membrane (Stage 4): Every 2-3 years.
- Post Filter (Stage 5): Every 12 months.
A TDS meter is the best tool to monitor membrane performance. If the TDS of the purified water starts to rise significantly, it’s time for a change.
Q2: Is the installation complicated?
A: The RWU UAR 1000 is designed for a straightforward DIY installation for those who are handy, typically taking 1-2 hours. It requires connecting to the cold water line, drilling a hole in the sink for the dedicated faucet, and connecting a drain line to the sink’s drain pipe. Comprehensive instructions are included. If you’re not comfortable, hiring a plumber is recommended.
Q3: How much water can it produce per day?
A: The system’s production rate is limited by the RO membrane’s capacity, not the tank. A standard membrane for this unit has a rating of 75-100 Gallons Per Day (GPD). The 3.1-gallon storage tank ensures you have a ready supply of water even when the membrane is slowly producing it.
Q4: Does it remove healthy minerals from water?
A: Yes, the RO process removes virtually all minerals, including calcium and magnesium. Some argue this makes the water less beneficial, while others prioritize the removal of harmful contaminants. You can add a remineralization filter after the post-carbon stage to reintroduce beneficial minerals like calcium and magnesium for improved taste and potential health benefits.
Q5: Why is there wastewater, and can it be reduced?
A: Wastewater is essential. It carries the rejected contaminants away, preventing the membrane from fouling and extending its life. You cannot eliminate it, but you can reduce it by:
- Ensuring your home’s water pressure is optimal (ideally 60+ PSI).
- Adding a permeate pump, which significantly reduces wastewater by up to 80% by harnessing the drain line’s hydraulic energy to assist the incoming pressure.
- Using an automatic shut-off valve, which the UAR 1000 includes, to stop production once the tank is full.
Q6: Where can I buy genuine replacement filters?
A: Always purchase from authorized dealers or reputable online retailers to ensure you get genuine, high-quality filters compatible with the RWU UAR 1000. Using off-brand filters can damage the system and void warranties.
Conclusion
The RWU UAR 1000 represents a robust and efficient solution for achieving high-purity drinking water directly from your tap. Its 5-stage filtration process, large storage capacity, and relatively efficient wastewater ratio make it a standout choice for families concerned about water quality. By understanding its operation, performing simple calculations to monitor efficiency, and adhering to a regular maintenance schedule, you can enjoy clean, great-tasting water for years to come.