iSpring RCC7 vs RCC7AK: One Stage Makes All the Difference
The RCC7 and RCC7AK are nearly identical systems. Same NSF certification, same membrane, same installation. The only difference is a single filter stage — and whether that stage is worth the price premium is what this comparison settles.
Quick answerGet the RCC7AK. The alkaline stage is worth the $20-40 extra.
For most households, the upgrade cost is trivial compared to the daily improvement in water taste. RO water without remineralization tastes noticeably flat. The RCC7AK fixes that. Unless you have a specific reason to skip the alkaline stage, it's the better buy.
| Feature | iSpring RCC7AK | iSpring RCC7 |
|---|
| Filtration stages | 6 (with alkaline remineralization) | 5 (no alkaline stage) |
| NSF/ANSI 58 certified | Yes — full system | Yes — full system |
| Flow rate | 75 GPD | 75 GPD |
| RO membrane | Same — 0.0001 micron | Same — 0.0001 micron |
| Output water pH | 7.5–8.0 (alkaline balanced) | 6.5–7.0 (slightly acidic) |
| Minerals in water | Yes — calcium, magnesium, potassium added back | No — RO removes all minerals |
| Water taste | Natural, spring-water character | Clean but flat |
| Annual filter cost | $60–$100 | $50–$80 |
| Price difference | ~$20–$40 more than RCC7 | ~$20–$40 less than RCC7AK |
| Filter compatibility | RCC7AK-specific filter sets | RCC7-specific filter sets |
What the alkaline stage actually does
Reverse osmosis is very thorough — it removes virtually everything dissolved in water, including the calcium and magnesium that give water its natural mineral character and mild alkalinity. The output is very pure, but slightly acidic and mineral-free.
The RCC7AK's 6th stage runs the purified water through a natural mineral filter that selectively adds calcium, magnesium, and potassium back in — the same minerals found in good spring water. The result is a water pH of 7.5–8.0 and a noticeably more natural, full taste.
When the RCC7 makes sense
- You're on a tight budget and every dollar matters
- You plan to add a separate remineralization cartridge inline
- You connect the output primarily to a refrigerator or ice maker
- You already drink standard 5-stage RO and are happy with the taste
When the RCC7AK is the clear choice
- Daily drinking water is the primary use
- Family members find RO water flat or prefer spring water taste
- The $20–40 price difference isn't a concern
- You want everything built in — no add-on cartridges needed
iSpring RCC7AK on Amazon →iSpring RCC7 on Amazon →Related pages