The iSpring RO5004F is a tankless, under-sink reverse osmosis system with a manufacturer-rated purified-water capacity of up to 500 gallons per day (0.35 gallons per minute). That rating is not a promise of the output a particular home will get: feed-water conditions and actual use matter. Before choosing it, check that your supply is municipal water, its pressure and temperature fall within the manual’s limits, and an appropriate electrical connection is available.
What is the iSpring RO5004F?
iSpring describes the RO5004F as a six-layer tankless reverse osmosis system for under-sink installation. Its product page lists UV, a built-in pump, a filter-life monitor, a leak-stop valve and a self-cleaning feature. These are manufacturer-described features, not independent performance findings. iSpring also describes the system as reducing PFAS, TDS, lead and arsenic, but the available product materials do not provide an RO5004F-specific independent test report or individual reduction rates. Do not read that marketing language as a quantified removal guarantee or proof of a health outcome. iSpring RO5004F product page.
The manufacturer lists dimensions of 15.20 × 6.10 × 16.60 inches and a product weight of 15 lb. Use those figures as a first check for cabinet space, while leaving room for the plumbing, electrical connection and service access required by the installation. iSpring RO5004F product page.
How much water does the RO5004F produce?
iSpring rates purified-water flow at up to 500 GPD, equivalent to 0.35 GPM, in its RO5004F Series manual. This is the manufacturer’s rated capacity, not a guaranteed household production rate or a statement of how much water will be available at every tap under every condition. iSpring RO5004F Series manual.
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- Affordable Replacement Filters: Our replacement filters are priced competitively, ensuring you get high-quality filtration without overspending. Choose the F4RO5004F 1-year pack or the F9RO5004F 2-year pack for long-term savings and hassle-free maintenance.
- 1000+ Contaminants Removal: Independently tested by SGS for PFAS and TDS reduction. This tankless reverse osmosis water filter eliminates over 99% of 1,000+ harmful contaminants, including PFAS (PFOA and PFOS), vinyl chloride, chlorine, fluoride, lead, arsenic, asbestos, calcium, sodium, and others.
- 6-Layer Filtration with UV Protection: This reverse osmosis water filter features an advanced 6-layer filtration system, including a PP sediment filter, anti-scale filter, CTO, 0.0001-micron RO membrane, taste-polishing CTO filter, and a built-in UV light that lasts up to 8,000 working hours. The water filter for sink also includes a status indicator to monitor UV function, ensuring safe and clean water.
- Tankless Design for Space-Saving: This reverse osmosis system under sink saves valuable under-sink space by eliminating the need for a storage tank.
- Built-In Pump for Low Water Pressure: The RO5004F includes a pump that addresses low water pressure, enhancing RO membrane efficiency for faster water output. The pump operates quietly for a more comfortable experience.
RO5004F installation requirements
The manual specifies the following incoming-water and electrical conditions. Check the supply and planned connection against the manual before installation; a reading outside the stated ranges does not meet the listed operating requirements.
| Requirement | iSpring specification |
|---|---|
| Feed water | Municipal water |
| Incoming water temperature | 41–100°F |
| Incoming water pressure | 30–70 psi |
| Rated power input | 110–240 V, 50/60 Hz |
| Rated voltage | DC 24 V |
| Rated current | 0.6 A |
| Maximum power input | 73 W |
These are manufacturer specifications from the undated RO5004F Series manual, accessed in 2026; they are not measurements of a particular home’s supply. The product page and manual do not establish that the system is suitable for non-municipal feed water. Consult the manual for the full installation procedure and confirm any site-specific plumbing or electrical questions with a qualified installer. iSpring RO5004F Series manual.
Rank #2
- SAVE BIG IN THE LONG TERM: With 20 years of industry experience, we know that maintenance can be a significant cost. Our replacement filters, including FP500, FC500SL, MRO5004F, and FG500AK, offer great value, are made with quality materials, and last longer.
- MINERAL BOOST: The natural mineral AK stage adds essential minerals back to your water, delivering natural spring-tasting water with a balanced, healthy pH and multiple essential minerals.
- EFFECTIVE FILTRATION: Independently tested by SGS for PFAS and TDS reduction. This tankless reverse osmosis water filter eliminates over 99% of 1,000+ harmful contaminants, including PFAS (PFOA and PFOS), TDS, vinyl chloride, chlorine, fluoride, lead, arsenic, asbestos, calcium, sodium, and more.
- PATENTED DESIGN – The top-mounted fastener allows for easy countertop installation entirely from above, eliminating the hassle of tightening the nut from underneath the sink.
- UV PROTECTION: The built-in UV light lasts up to 8,000 hours and includes filter lifespan monitoring to ensure regular maintenance for optimal performance.
RO5004F replacement filters
iSpring lists these individual replacement parts for the RO5004F:
| Part number | Manufacturer-listed role |
|---|---|
| FP500 | Sediment filter |
| FC500SL | Anti-scale/activated carbon filter |
| MRO5004F | 500 GPD RO membrane |
| FC500 | Taste-polishing CTO filter |
The product listings also identify F4RO5004F as a one-year replacement pack and F9RO5004F as a two-year replacement pack. These are pack descriptions, not a guarantee that every household can wait that long to replace filters: iSpring says lifespan depends on water quality and use. Check the product listing and pack contents against the precise system model before ordering. iSpring RO5004F product page; iSpring RO500-series replacement filters.
Rank #3
- Dedicated 1-year water filter replacement pack (FP500x2, FC500SLx1, FC500x1) for iSpring RO5004F Tankless Reverse Osmosis System
- The first-stage sediment water filter cartridge captures fine particles down to 5 microns, including sand, silt, rust, and sediments.
- Anti-Scale+Activated Carbon water filter cartridge eliminates chlorine, odors, and other impurities for cleaner water while protecting appliances and plumbing by preventing scale buildup
- The carbon block water filter cartridge refines and polishes the taste of your drinking water.
- Quick and easy filter change
RO5004F vs. RO5004F-AK
The RO5004F-AK is a separate alkaline variant, not another name for the standard RO5004F. iSpring describes the AK as a seven-layer system and lists an FG500AK alkaline filter for it. The standard RO5004F product materials do not list that alkaline stage. If you are replacing filters or comparing the models, use the model-specific parts and product details rather than assuming their components are interchangeable. iSpring RO5004F-AK product page.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What the available certification information establishes
iSpring’s RO500-series category page says that F3-RO500 and certain RO500-series packs are NSF/ANSI 58 certified, while listing RO5004F replacement packs separately. That wording does not establish certification for the RO5004F system or its F4RO5004F and F9RO5004F packs. Do not transfer a certification statement for another product in the series to this model. iSpring RO500-series category page.
Quick Recap
Best Value
- Replacement cycle: FP500 (up to 6 months), FC500SL (up to 12 months), FG500AK (up to 12 months).
- Dedicated 1-year water filter replacement pack (FP500x2, FC500SLx1, FG500AKx1) for iSpring RO5004F-AK Tankless Reverse Osmosis System
- The first-stage sediment water filter cartridge captures fine particles down to 5 microns, including sand, silt, rust, and sediments.
- Alkaline+Activated Carbon water filter cartridge eliminates chlorine, odors, and other impurities for cleaner water while replenishing the water with beneficial minerals to improve taste and quality.
- Anti-Scale+Activated Carbon water filter cartridge eliminates chlorine, odors, and other impurities for cleaner water while protecting appliances and plumbing by preventing scale buildup.
Rank #4
- PATENTED DESIGN – The top-mounted fastener allows for easy countertop installation entirely from above, eliminating the hassle of tightening the nut from underneath the sink.
- MINERAL BOOST – The patent-pending natural mineral AK stage delivers spring water with a balanced, healthy pH and multiple essential minerals.
- SEE WHAT’S CAUGHT – The transparent first-stage filter housing makes it easy to monitor contaminant buildup, ensuring timely filter changes.
- NSF 58 CERTIFIED RO SYSTEM – Unlike other brands that lack NSF certification or full system certification, our RCC7AK is certified to NSF/ANSI 58 standards for the entire water filtration system.
- EFFECTIVE FILTRATION – Reduces TDS (93-98%), PFAS (96-99%), Chlorine (95-99%), Asbestos (>99.7%), Barium (>98.4%), Cadmium (>98.8%), Chromium (>99.2%), Copper (>97.8%), Fluoride (>97.4%), Lead (>98.9%), Selenium (>99.0%), and over 1,000 other contaminants.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
