NSF Certified vs iSpring RCC7AK: Surprising RO Insight for Under-Sink Use We were intrigued by the iSpring RCC7AK’s NSF certification and its unique alkaline pH+ remineralization feature. As we installed our unit, the patented top-mounted faucet design impressed us for its simplicity and space-saving benefits. The 75 GPD flow rate delivers consistent, high-quality water, and the 6-stage filtration—removing impurities while adding minerals—felt like a thoughtful upgrade. While NSF certification ensures safety, we were surprised by how the remineralization stage balanced acidity, resulting in softer, more refreshing water. The system’s quiet operation and sleek under-sink integration made it a practical choice, though we noted the need for periodic filter replacements. Overall, the RCC7AK delivers a surprising blend of purity and natural alkalinity, making it a standout choice for us seeking both peace of mind and enhanced hydration.