Viomi M1 vs Waterdrop G5P500A: Matching Output and Monitoring to Your Household

Household water needs set these two purifiers apart, since both add minerals back after reverse osmosis: one pairs a touchscreen faucet showing tap and purified TDS with preset volumes, the other a hand-operated tap with filter alerts on the main unit. A home where several people draw water through the day and want to read tap and purified TDS right at the faucet is well suited to the Viomi M1, since its touchscreen faucet carries both readings and pours preset volumes with one touch.

The Waterdrop G5P500A takes a simpler approach. In its WD-G5P500A version, it pairs a mechanical faucet with filter-life lights on the main unit, a familiar setup for a household that likes to open and close the tap by hand.

Output, Faucet and Mineralization Side by Side

On output, the Viomi M1 carries a 1000 GPD membrane rating, and Waterdrop rates the G5P500A at 500 GPD of maximum daily production under the test conditions in its manual. These are daily production figures, so neither one is a faucet flow speed. With no storage tank on either side, water is made when someone opens the faucet, and the cabinet holds the main unit and its tubing with no tank beside it. In filtration terms, the Viomi M1 uses 9-stage filtration built around a 0.0001-micron RO membrane, and the G5P500A uses 8 stages, one more than Waterdrop's non-mineral G5P500, the extra stage being its mineral layer. Each system packs its stages into two cartridges, one of which carries the mineral stage.

Busy Kitchens and Larger Households

When two or three people cook in the evening and bottles get filled for school and work each morning, water is drawn in many small and large amounts through the day, and the Viomi M1 is built to fill pitchers, coffee makers, pots and reusable bottles on demand. Each fill is purified and then mineralized as it is drawn, and its 1000 GPD rating is the higher of the two production ratings. Automatic flushing is built into the system as well, alongside one-touch dispensing at the faucet.

Large fills are easier to manage from the touchscreen. One touch pours one of three preset volumes, including 10 oz for a glass and 40 oz for a pitcher, so the morning round of bottles can be filled to the same amount each time without watching a measuring cup. A household that also wants filtered ice or chilled water can connect the Viomi M1 to a compatible refrigerator or ice maker using standard tubing and the tee fitting packed in the box, with "Multi-device Mode" switched on in the Viomi app, a setting that lets the system supply the appliance line as well as the faucet, so the sink and the appliance share one purified supply. For a busy household, that means one system and one set of cartridges behind the drinking water, the ice and the cooking water, with a single set of filter-life readings to follow.

Seeing Water and Filter Data at a Glance

The two systems show their information in different places. The Viomi M1 puts it on the faucet: a tap-water TDS reading for the water coming in, a purified-water TDS reading for the water going out and the remaining life of the PCB and RO cartridges. TDS, short for total dissolved solids, is the total of solids dissolved in the water, mostly minerals and salts, so the two readings show the starting point and the result. The faucet is wired to the main unit, so its readings come from the system itself, and the app adds a second view on the phone. The Viomi app shows the same filter life along with the system's water usage and inlet water temperature. When a cartridge reaches its rated end, the app sends a notification to the phone and the main unit's RO lamp glows orange, so the reminder reaches whoever looks after the system even away from the kitchen. Our roundup of RO brands with TDS monitoring shows how other systems handle these readings.

The G5P500A tracks filter status on its main unit. The front panel has a filter-life indicator for the CF cartridge and another for the RO cartridge, and each changes color from blue to yellow to red as its cartridge nears replacement, with beeps as an added reminder. Because both indicators sit together on the front panel, one look at the main unit shows the status of both cartridges. Its faucet is mechanical, opened and closed by hand like a standard tap, an arrangement many households find familiar.

For a broader comparison of the two approaches, our guide to smart and traditional water filter brands covers the trade-offs.

Everyday Use With a Mechanical Faucet

A couple, a single person or a small family that mostly fills glasses, a pitcher and a kettle may simply want purified, alkaline water from a familiar faucet, and the G5P500A offers that with a mechanical faucet. Its cartridge set comes to two cartridges in all, and its built-in mineral layer gives alkaline water without any added cartridge.

The mechanical faucet suits people who like a hand-operated tap, and the color-changing panel lights and beeps give a clear signal when a cartridge is due. The G5P500A-CF cartridge, which holds the mineral layer, is rated for up to 6 months, so the mineral stage is renewed with each CF change; that one cartridge combines pre-sediment filtration, a post-carbon block and the alkaline layer, and the G5P500-RO is rated for up to 24 months. On drain water, the 2:1 rating means one part goes to the drain for every two parts purified.

How Each System Adds Minerals Back

Both systems put minerals back inside a composite cartridge, so neither one adds a separate mineral housing under the sink, and neither asks the household to order a mineral cartridge on its own. On the Viomi M1, the M1-PCB cartridge removes sediment, chlorine and organic matter ahead of the membrane, protecting the RO stage, and after purification it reintroduces six selected minerals, calcium, magnesium and potassium among them. The result at the faucet is low alkaline water, and because minerals are added back on purpose, the Viomi M1's purified TDS reading sits higher than that of standard RO water, which is expected. On the faucet, the purified figure therefore includes the added minerals, while the tap-water figure shows the incoming supply before treatment.

The G5P500A carries its alkaline mineralization layer in the G5P500A-CF cartridge, which combines pre-sediment filtration with a post-carbon block. Waterdrop says the layer adds calcium, magnesium, sodium and potassium and brings the water to a pH of around 7.5.

A reverse osmosis membrane removes most dissolved minerals along with the substances it is designed to reduce, so the water leaving the membrane carries very little dissolved content. A mineral stage after the membrane puts some of that content back, which is why both systems describe their output as alkaline and why the mineral content shows up in the TDS reading. For households weighing alkaline systems more broadly, our overview of alkaline reverse osmosis system brands lays out the wider field.

FAQ

Does a 1000 GPD system send more water down the drain?

The daily production rating and the pure-to-drain ratio are separate figures: one describes rated capacity, the other the rated balance between purified water and drain water. The Viomi M1 is rated at 3:1, one part to the drain for every three parts purified, and the G5P500A at 2:1, one part for every two. A higher GPD rating does not change either system's rated ratio, so for a household weighing drain water, the ratios are the figures to compare.

How does a mechanical faucet differ from a touchscreen faucet day to day?

On the Viomi M1, dispensing starts with a touch, the preset volumes are on the same screen and the TDS and filter-life readings are visible whenever the faucet is used. The G5P500A's mechanical faucet is opened and closed by hand like a standard tap, and its main unit's panel lights and beeps signal when the CF or RO cartridge is due.

How long do the mineral cartridges last on each system?

The Viomi M1-PCB, which handles pre-filtration ahead of the membrane and carries the mineral stage, is rated for up to 24 months, and the M1-RO1000 for up to 48 months. Each twists out by hand, no tools needed, and once the new cartridge is in, a filter-life reset brings the readout back to 100% on the faucet and in the Viomi app, which then counts down the remaining life again. On the G5P500A, the G5P500A-CF with its mineral layer is rated for up to 6 months and the G5P500-RO for up to 24 months, so on those ratings one RO service life spans four CF service lives, and the mineral layer is renewed with each new CF cartridge.

What does setting up each system involve?

Both take feed water from the standard cold-water supply line and run a drain line to the sink drain. The Viomi M1's installation parts ship in the box, and a step-by-step installation video covers each connection in order, from the feed-water adapter to the faucet and drain, so the setup can be followed one connection at a time. Its main unit measures 17.1 inches deep, 6.4 inches wide and 15.9 inches high. For the G5P500A, Waterdrop's manual asks for about 2 inches of clearance around the main unit.

Does either system need a storage tank?

Neither does. Both are tankless under-sink systems that make purified water as it is drawn, so the cabinet holds the main unit and its tubing with no tank beside it. On the Viomi M1, the same applies when a refrigerator or ice maker is connected: the appliance line draws from the system as it needs water, and the filter-life readings on the faucet and in the app cover both uses. The G5P500A likewise makes water as it is drawn, with its mineral layer carried in the CF cartridge.

Sizing the Choice to Your Household

Feeding a refrigerator or ice maker, pouring preset amounts and reading tap and purified TDS at the faucet all point to the Viomi M1. Opening and closing the tap by hand, with filter alerts on the main unit and an alkaline layer built into the CF cartridge, points to the G5P500A.