When buying a water purifier, flux parameters like "600G", "800G" and "1200G" often make people confused—choose a too-small one and you’ll wait anxiously for slow water flow; choose an oversized one and you’ll worry about wasting money? Actually, the core of flux (GPD, Gallons Per Day) lies in "water output per unit time" (1G ≈ 3.785L), and whether it’s suitable depends entirely on your household’s water usage scenario. Today, we’ll provide a precise purchasing list based on the needs of single-person households, families of three, and multi-generational families (with 5-6 members), combining water flow efficiency and long-term costs. We’ll also recommend matching INTOPAQUA TANKLESS RO bucketless series models to help you avoid unnecessary expenses.
First, Understand: Higher GPD ≠ Better; the Key Lies in "Water Usage Frequency + Number of People"
Many people think "the higher the GPD, the more advanced the machine", but they ignore two core points:
- GPD corresponds to water output and is related to cost: Higher flux means faster water output per use, but the initial purchase cost and subsequent filter replacement cost will be slightly higher; on the contrary, small-flux models are cheaper, but it may take 1 minute to fill a kettle, which affects the user experience.
- GPD of bucketless models is more "authentic": The GPD of traditional bucket-equipped RO machines is a comprehensive value of "water storage bucket + membrane flux", and the actual real-time water output is much lower than the marked value; while the INTOPAQUA TANKLESS RO series adopts a "bucketless, filter-while-drinking" design. The marked 600G/800G/1200G is the real real-time water output, with no "false marking" issue, making it more worry-free to choose.
In short: The essence of choosing flux is to make the "water output" exactly match the "peak water demand of the household", ensuring no lag and no waste.
Choose Flux by Scenario: A Precise Matching List for 3 Types of Households
We took "daily peak water usage (8 AM for milk preparation/coffee brewing, 7 PM for vegetable washing/direct drinking water collection)" as the test scenario, calculated the water flow efficiency (time to fill a 1.5L kettle) and annual cost (purchase + filter replacement, based on a 3-year usage cycle) of different fluxes, and then matched them with INTOPAQUA TANKLESS RO models to provide specific recommendations.
1. Single-person/Lone-dwelling Households: 600G is Sufficient, the Cost-effective Choice
Water Usage Characteristics: Only 1-2 times of concentrated water usage per day, mostly for collecting direct drinking water and cooking noodles. The water volume per use is small (≤500ml), and there’s no need for simultaneous water use.
Efficiency Calculation: The INTOPAQUA TANKLESS RO 600G model has a real-time water output of about 1.5L/min. It takes only 8 seconds to fill a 200ml cup of direct drinking water and 1 minute to fill a 1.5L kettle—no waiting at all.
Cost Calculation: The purchase price is about 1,500-1,800 yuan. Equipped with a 3-year long-life RO membrane (annual filter replacement cost of 200 yuan), the total cost over 3 years is about 2,100-2,400 yuan, which is only 2 yuan per day. It’s suitable for singles with limited budgets who pursue practicality.
Recommended Model: INTOPAQUA TANKLESS RO 600G Under-sink Type (Model: IT-RO600C) — Compact in size, suitable for small cabinets in single-person apartments. It supports APP filter reminder, allowing easy maintenance even for lone dwellers.
2. Families of Three (with Children): 800G is Suitable, Balancing Efficiency and Cost
Water Usage Characteristics: Peak water usage in the morning (parents brew coffee + prepare milk for children) and evening (wash vegetables + collect direct drinking water + wash fruits for children). There are 3-4 times of concentrated water usage per day, and "2 people using water simultaneously" often occurs (e.g., collecting direct drinking water on one side and using purified water to wash dishes on the other).
Efficiency Calculation: The INTOPAQUA TANKLESS RO 800G model has an increased water output of 2.0L/min. It takes 6 seconds to fill 200ml of milk-making water and 45 seconds to fill a 1.5L kettle; even if 2 people use water at the same time, the water output won’t decrease significantly, avoiding "delays in making breakfast due to waiting for water".
Cost Calculation: The purchase price is about 1,800-2,200 yuan. Also equipped with a 3-year long-life RO membrane (200 yuan for annual filter replacement), the total cost over 3 years is 2,400-2,800 yuan, which is 2.2-2.6 yuan per day. Compared with the 600G model, it only costs 300-400 yuan more but solves the problem of "queuing for water", offering higher cost-effectiveness.
Recommended Model: INTOPAQUA TANKLESS RO 800G All-round Model (Model: IT-RO800Pro) — With dual water outlets (direct drinking water + daily use water), direct drinking water is used for milk preparation, and daily use water for vegetable washing, which saves filters and ensures longer service life; it has a high-definition screen on the body, allowing the elderly to clearly see the filter life.
3. Multi-generational Families (5-6 Members): 1200G is a One-stop Solution for High-frequency Water Usage
Water Usage Characteristics: Peak water usage in the morning (3 people brushing teeth + 2 people preparing milk/coffee) and evening (cooking + washing vegetables + collecting direct drinking water + making medicine for the elderly). There are 5-6 times of concentrated water usage per day, and "3 people using water simultaneously" frequently occurs (e.g., collecting water in the kitchen, getting direct drinking water in the living room, and watering flowers with purified water on the balcony), requiring extremely high water output.
Efficiency Calculation: The INTOPAQUA TANKLESS RO 1200G model has a high water output of 3.0L/min. It takes only 4 seconds to fill 200ml of water and 30 seconds to fill a 1.5L kettle; even if 3 faucets are used at the same time, the water flow remains stable without "slowing down as it’s used", fully adapting to the "intensive water usage demand" of large families.
Cost Calculation: The purchase price is about 2,300-2,600 yuan. With a 3-year long-life RO membrane (220 yuan for annual filter replacement), the total cost over 3 years is 2,960-3,260 yuan, which is 2.7-3 yuan per day. Although it’s more expensive than the 800G model, it avoids the secondary cost of "replacing with a larger model", making it more cost-effective in the long run.
Recommended Model: INTOPAQUA TANKLESS RO 1200G Large Flux Model (Model: IT-RO1200Max) — Equipped with dual-pump pressure boosting technology, it ensures stable water output even in high-rise buildings; it supports whole-house water purification linkage and can be matched with a pre-filter, suitable for long-term use in large apartments.
Pitfall Reminder: Don’t Ignore These 2 Details When Choosing Flux
- Don’t just look at GPD; recognize "bucketless, filter-while-drinking": As mentioned earlier, the GPD of traditional bucket-equipped machines is "false". For example, a machine marked 800G may only have an actual real-time water output of 400G; while the INTOPAQUA TANKLESS RO series adopts a bucketless design, where GPD = real water output. When buying, make sure to check if it’s "bucketless" to avoid being misled.
- Choose "clog-resistant models" based on local water quality: If you live in northern China (where water quality is hard and has many impurities), even if you choose the right GPD, the water output may decrease due to filter clogging. The entire INTOPAQUA TANKLESS RO series is equipped with "clog-resistant PPC composite filters", which can intercept sediment and rust in advance, prolonging the service life of the RO membrane. Families in northern China can choose with confidence.
Summary: A Table to Solve Household Flux Selection
Choosing the flux of a water purifier is essentially "matching on demand"—there’s no need to blindly pursue large GPD, nor to choose a small one to save money and affect the experience. If you’re not sure which one is suitable for your home, you can visit the INTOPAQUA official website (https://www.intopindustry.com/), enter the number of family members and water usage habits to get exclusive flux recommendations; you can also watch the real test videos of the TANKLESS RO series models to intuitively feel the water output speed of different fluxes and buy with more confidence.
