The iSpring RCC7 has been one of the top-selling under-sink RO systems on Amazon for years. That’s not an accident. It hits a combination of NSF certification, DIY-friendly installation, US-based customer support, and a price point most households can manage.
This review covers the RCC7 and its variants, based on NSF certification data and manufacturer documentation.
iSpring Background
iSpring is based in Alpharetta, Georgia. The company was founded in 2009 and has been one of the more consistently recommended under-sink RO brands in the US residential market. They’re known for US-based customer support, which matters when you’re troubleshooting a leak under your sink at 7pm.
The product line covers under-sink RO systems, whole-house filters, and a few commercial options. The RCC7 is the flagship residential model and the one most people encounter.
NSF Certifications
iSpring holds:
- NSF/ANSI 58 (reverse osmosis performance)
- NSF/ANSI 372 (lead-free components)
NSF 58 is the core certification for RO systems. It covers contaminant removal performance, structural integrity, and material safety. You can verify iSpring’s certification at info.nsf.org.
For NSF P473 (the specific standard for PFOA and PFOS), check the model you’re buying. NSF 58 certified RO systems remove PFAS through the RO membrane process. P473 adds a specific independent verification step for PFAS compounds.
What RO Removes
RO membranes remove dissolved contaminants by forcing water through a semipermeable membrane at pressure. What passes through is primarily water. What doesn’t:
- PFAS compounds removed via the RO membrane
- Fluoride: approximately 94 to 97% reduction
- Arsenic: approximately 94% reduction
- Nitrates: approximately 85 to 93% reduction
- Lead: approximately 95% reduction
- Chromium-6
- Chloramine and chlorine (via carbon pre-filters)
- Dissolved minerals and pharmaceuticals
These rates are per NSF 58 certification and manufacturer documentation. Source water varies by region, so test your water before choosing treatment to confirm what you’re actually dealing with.
The Models
iSpring RCC7AK (6-stage, with re-mineralization)
This is the model most people should consider first. The RCC7AK adds a 6th stage after the standard 5-stage RO process: a remineralization filter that adds calcium and magnesium back into the filtered water.
RO strips out essentially all dissolved minerals, which produces water with a slightly flat taste and pH below 7. The remineralization stage brings pH back up to around 7 to 7.5 and restores a small amount of mineral content that improves taste for most people.
The health claims around alkaline and remineralized water are largely unsupported by clinical evidence. But taste improvement from remineralization is real and well-documented in user feedback.
Priced around $190 to $220.
Check current pricing (affiliate link, see disclosure above)
iSpring RCC7 (5-stage, no remineralization)
The original. Same RO performance as the RCC7AK without the remineralization stage. If you don’t care about pH or mineral taste, this is the same filtration for less money.
Rated at 75 GPD. 3.2-gallon pressurized storage tank. Priced around $170 to $200.
Check current pricing (affiliate link, see disclosure above)
iSpring RCC1UP-AK (tankless, with UV)
A newer addition to the lineup. Tankless design (no pressurized storage tank), 400 GPD rated, UV sterilizer included, plus remineralization. More compact than the RCC7 series.
Priced around $250 to $300. A good choice if you want to reduce cabinet footprint while staying with a US-backed brand.
Check current pricing (affiliate link, see disclosure above)
iSpring WGB32B (whole-house, 3-stage)
Not an RO system. The WGB32B is a whole-house sediment and carbon filter for city or well water pre-treatment. Removes sediment, chlorine, and chloramines across all household water. Doesn’t remove PFAS, fluoride, or nitrates. Useful for well water households who want to reduce sediment and chlorination throughout the house before point-of-use treatment. Priced around $175.
Installation
Most homeowners install the RCC7 in 1 to 2 hours. The system connects to the cold water supply line under the sink using a simple saddle valve (included), routes a drain line to the P-trap or disposal, and connects to a dedicated faucet that mounts in an existing hole or a new hole you drill.
iSpring includes color-coded tubing, an illustrated manual, and all required hardware. The connections are push-fit, which means no soldering or special tools.
The RCC7 doesn’t have a filter life indicator or digital display. You replace filters on a schedule, not on a sensor. Set a calendar reminder at installation.
If you’re not comfortable under a sink at all, a plumber can install it in under an hour.
Tank-Based Design: What It Means
The RCC7 uses a 3.2-gallon pressurized storage tank. Here’s how that works:
The RO membrane produces filtered water slowly (75 GPD is about 3 gallons per hour under normal pressure). Instead of waiting for the membrane each time you open the tap, the tank stores pre-filtered water and delivers it at normal faucet pressure when you want it.
The tradeoff is cabinet space. A 3.2-gallon tank is about the size of a large gallon jug. In smaller under-sink cabinets, it takes up significant space. Tankless designs like Waterdrop solve this by filtering on demand with a pump, but at the cost of slight pressure variation.
For households with adequate cabinet space, the tank-based system delivers consistent, instant water at normal pressure without complexity.
Waste Water
The RCC7 produces approximately 3 gallons of drain water per 1 gallon of filtered water. This is standard for tank-based residential RO systems.
Tankless systems like Waterdrop’s G-series achieve 2:1 ratios. If water efficiency matters for your household, that’s a real difference. For most households on city water, the RCC7’s ratio doesn’t produce a meaningfully higher water bill.
Filter Replacement Schedule and Costs
| Stage | Function | Replaces Every | Approx Cost |
|---|---|---|---|
| Stage 1 (sediment) | Removes particles | 6 to 12 months | $5 to $8 |
| Stage 2 (carbon block) | Chlorine, organics | 6 to 12 months | $10 to $15 |
| Stage 3 (carbon block) | Further chlorine | 6 to 12 months | $10 to $15 |
| Stage 4 (RO membrane) | Core filtration | 24 to 36 months | $25 to $40 |
| Stage 5 (post-carbon) | Final taste polish | 12 months | $8 to $12 |
Annual operating cost: approximately $60 to $100. Replacement filters are available on Amazon, at Home Depot, and direct from iSpring. Third-party compatible filters exist for all stages.
How iSpring Compares to Waterdrop
Both are NSF 58 certified under-sink RO systems at a similar price range.
iSpring differentiates on US-based customer service, longer track record, and the consistent pressure of a tank-based system. Waterdrop differentiates on compact form factor (tankless), slightly better waste water efficiency (2:1 vs. 3:1), and a more modular filter replacement system.
If you have the cabinet space and want a well-proven system with US support, iSpring RCC7AK is a reliable choice. If space is tight and you want tankless, Waterdrop is worth comparing.
The Recommendation
iSpring RCC7AK is a well-proven, DIY-friendly under-sink RO option. The NSF 58 certification is real. Customer service is US-based. Installation is manageable for most homeowners with basic plumbing confidence.
It’s not the most efficient system on waste water, and the tank takes up cabinet space. But it delivers consistent RO-grade filtration at a price that’s held steady for years.
For a full comparison against other under-sink options, the best under-sink RO systems page covers iSpring alongside Waterdrop, Aquasana, and others side by side.