VIVA21 by Filter United
Reverse Osmosis Systems. Better water, every day.
Bring great-tasting water home with VIVA21 under-sink reverse osmosis systems. Keep it flowing with replacement filters, membranes, and everyday essentials from Filter United.
- Removes up to 99% of contaminants - PFAS, heavy metals, chlorine, and more.
- Built by a team with over 35 years of combined experience in water filtration industry.
- WQA Gold Seal certified to meet the strict NSF 58 and NSF 372 standards.
- Peace of mind - lifetime limited parts warranty and support.
- Under-sink Filtration
- Universal Fit Replacement Filters
- Lifetime Customer Support
What Our Customers Say
Margot B.
Budget RO system that works & cheaper than big-box stores.
This VIVA21 5-stage RO system is...
Mr. Aloha Friday
They are 5 micron, they fit, water tastes...
George C.
Flexible design! Perfect for Renovations!
I really like how modular the VIVA21 system is. It fit perfectly under my sink...
P. Jones
Good lower capacity system...
Phemsley
Nice set of Backup filters for RO System.
Nice replacement filters for my iSpring RO system. They are a reasonable price...
Will H.
Water tastes great...
Ryder D.
Great reverse osmosis replacement filter set!
This is a reverse osmosis water filtration...
Gregory
High quality filters at a great price...
Find Your Next Essential
Shop for Better Water
VIVA21 by Filter United
Good water belongs in everyday life
From the first morning coffee to dinner at home, your water should work for you. VIVA21 brings under-sink reverse osmosis filtration into your routine, with replacement essentials and support from Filter United.
Lifetime Support
We built reliable reverse osmosis systems that work and are meant to elevate your wellness. Ask us anything or checkout our FAQs!
How long does shipping take?
How long does shipping take?
Shipping usually takes 2-7 business days, depending on your location.
We ship our package in 1 business day, and the rest is taken care of by selected shipping carrier.
What is PFAS and how is it removed?
What is PFAS and how is it removed?
PFAS are "forever chemicals" that accumulate in the body and environment, linked to cancer, hormone disruption, and immune dysfunction. They are widely found in U.S. water supplies and bottled water.
Our reverse osmosis system, VIVA21 effectively removes PFAS from your water and provide best quality drinking water right from your kitchen.
What is the warranty on your RO system?
What is the warranty on your RO system?
We offer an extra 2 years of system warranty with registration. Registration is free and simple, please register your systems here.
You also get lifetime limited warranty for your RO system parts.
What is a Reverse Osmosis System
What is a Reverse Osmosis System
A Reverse Osmosis (RO) system is a multi-stage water filtration system that uses a semipermeable membrane to remove most of the dissolved solids, chemicals, and impurities in your tap water. It forces water through the membrane under pressure, leaving contaminants behind. RO is known for producing exceptionally clean drinking water. It is widely used in homes for improved taste, safety, and purity.
Why should I choose an RO system over other filtration methods?
Why should I choose an RO system over other filtration methods?
RO systems remove up to 99% of harmful contaminants such as heavy metals, PFAS, nitrates, chlorine, fluoride, and micro-sediments commonly found in tap water, while carbon filters only remove taste and odor.
If you want truly purified drinking water, RO is the most effective household filtration technology.
How does an RO system work?
How does an RO system work?
A RO system typically filters water through several stages, including sediment, carbon blocks, and the RO membrane. The membrane allows water molecules to pass through while rejecting contaminants. Clean water is stored or delivered directly to the faucet, while wastewater is flushed away through the drain line. The result is purified drinking water with significantly reduced impurities.
Why is there “wastewater” in an RO system?
Why is there “wastewater” in an RO system?
Reverse osmosis produces “wastewater” because the system needs to flush away the contaminants it removes from your tap water.
During filtration, water is pushed through a membrane that blocks the impurities. The clean water passes through, while the concentrated contaminants must be carried out of the system through a small stream of “wastewater”.
This rinse water is essential. It prevents buildup on the membrane, keeps filtration performance high, and helps extend the life of the RO system.
Helpful Guides for Better Water
Life Flows Forward With VIVA21
Removes 99% of PFAS, Lead, chlorine, heavy metals, and more - with no electricity required. Enjoy crisp clean water with lifetime limited parts warranty and support.
With over 35 years of combined experience in water filtration system, we built the VIVA21 reverse osmosis system with the most reliable components for everyone.









