iSpring RO500AK Alkaline Reverse Osmosis System
- Capacity: 500 gallons
- Purification Method: Reverse Osmosis
- Installation Type: Under-Sink
- Supported Water Tds Level Maximum Ppm: 1000
Last refreshed Aug 4, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A capable under-sink RO system with a 500 gallon rated capacity and recent buyer volume, suited to households ready for a permanent under-sink install.
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ASIN: B09CHBC9CPModel: RO500AKCategory: Water Filtration Systems
Overview
The iSpring RO500AK-BN is an under-sink reverse osmosis filtration system rated for 500 gallons of capacity, measuring 17.5 x 5.2 x 16.25 inches and weighing 21 lb.
Unlike the cartridge style filters elsewhere in this batch, this is a full reverse osmosis system meant for under-sink installation rather than a single swap-in filter. Reverse osmosis pushes water through a semipermeable membrane, which typically removes a broader range of dissolved contaminants than carbon alone, though the listing does not break out which specific contaminants this unit targets.
- Reverse osmosis purification
- 500 gallon rated capacity
- Under-sink install type
- 17.5 x 5.2 x 16.25 in, 21 lb
Who it's for
Homeowners who want a dedicated RO system installed under the kitchen sink rather than a drop in fridge filter. Not for renters needing a no-install option, since this requires under-sink plumbing.
Pros and cons
- Full reverse osmosis filtration, not just carbon
- 500 gallon rated capacity
- Highest recent buyer volume in this batch
- Requires under-sink installation
- No stated membrane replacement interval
- 21 lb unit needs dedicated cabinet space
Performance notes
Reverse osmosis forces water through a membrane under pressure, which generally reduces a wider range of dissolved solids than a standard carbon cartridge. At 21 lb, the unit is sized for permanent placement rather than portability, and its 500 gallon capacity rating gives a sense of how long the membrane lasts before replacement, though the listing does not specify a replacement interval in months.
Specifications
| Brand | iSpring |
|---|---|
| Model | RO500AK |
| Dimensions & fit | |
| Weight | 21 poundshigher than 70% of 41 water filtration systems |
| Item Dimensions L X W X H | 17.5 × 5.2 × 16.2 inches |
| Capacity & performance | |
| Capacity | 500 gallonshigher than 82% of 46 water filtration systems |
| Upper Temperature Rating | 100 °F |
| Filter Life Cycle | 2 years |
| Maximum Flow Rate | 0.4 gpm |
| Lowertemperature Range | 41 °F |
| Operating Pressure Range | 15 psi |
| Power & efficiency | |
| Power Source | Corded Electric |
| Construction & materials | |
| Material Type | Reverse Osmosis Membrane & Carbon Block + PP Composite Filter& Carbon Alkaline Filter |
| Compatibility & installation | |
| Installation Type | Under-Sink |
| Included components | |
| Included Components | Tubing, System, Feed Water Adapter, Drain Saddle, Faucet, Power Supply, Manual |
| Warranty & support | |
| Supported Water Tds Level Maximum Ppm | 1000 |
| Warranty Description | 1 year |
| Other details | |
| Purification Method | Reverse Osmosis |
| Container Type | Box |
| Number Of Items | 1 |
| Other Special Features Of The Product | Tankless, Water Saver Technology |
| Part Number | RO500AK-BN |
| Item Highlight | Under Sink Tankless RO Water Filter, Fill 8 Oz In 10 S, 2:1 Low Drain Ratio, TDS PFAS Reduction, Auto Flush, Filter Reminder |
| Item Type Name | -BN Tankless RO Reverse Osmosis Water Filtration System, 500 GPD Fast Flow With Natural PH Alkaline Remineralization, Brushed Nickel Faucet, 2:1 Pure To Drain Ratio |
Closest rivals on specs
Waterdrop TSU Ultra Filtration Under Sink Water Filter- Weight 21 vs 14 pounds (+50%)
Waterdrop WD-T4-A Alkaline Reverse Osmosis System 450 GPD- Capacity 500 vs 450 gallons (+11%)
- Weight 21 vs 24.21 pounds (-13%)
Frequently asked questions
Is the RO500AK-BN a drop-in fridge filter?
No, it is a full under-sink reverse osmosis system, not a single cartridge swap.
How much space does it need under the sink?
It measures 17.5 x 5.2 x 16.25 inches and weighs 21 lb, so it needs dedicated cabinet space.
What is its rated capacity?
The system is rated for 500 gallons.