iSpringPH100 6-Stage Alkaline Under-Sink Reverse Osmosis System, 100 GPD

iSpring's under-sink RO systems are well represented in r/WaterTreatment, with an owner lab report showing arsenic to non-detect below 2 ppb and multi-year service reported on hard supplies. The recurring negative is a leak cluster at faucet handles and housing joints after cartridge changes, plus low-flow threads that resolve to tank pressure below specification, and two owners on one thread reporting early storage-tank failure. The US-made 100 GPD pair is not discussed by model, and nothing in the pool addresses the domestic-filter claim that is the reason to buy it.

No publication covers the US-made 100 GPD systems at all, in either editorial or laboratory form, which is a more complete absence than anything else in iSpring's range carries. Published lab work on the brand is on the tanked RCC7 chassis and reaches opposite verdicts: TechGearLab at 91 out of 100 and third of thirteen, WaterFilterGuru at 6.64 overall with contaminant reduction at 5.25 and measured production at roughly half the rated output, and RO-System.org withdrawing its recommendation of the line. None of it is about a system with US-made filters or a 1:1 waste ratio, which are the two claims that distinguish this one.

No independent channel has bench-tested the US-made 100 GPD systems, and the only video results for either model are installation walkthroughs. BOS Water's laboratory testing — the channel earns a commission on the system it tested — covers the alkaline RCC7 on a different chassis, where it found strong reduction alongside boron rising from 0.005 to 0.17 ppm, vanadium and trace aluminium in the filtered water; the comparison work on the brand covers the RO500 tankless line. Neither describes a system with US-made filters, which is the claim this pair is sold on.

The PH100 has its own Amazon listing and publishes no rating in readable form, and its sibling RO100 is not listed as a system at all, so neither US-made model carries a marketplace pool. Falling back: Amazon's brand panel puts 91 percent of iSpring ratings at four stars or better over 100,000-plus orders in the trailing three months, collected mostly on cartridges and on the mainstream RCC7 line rather than on US-made hardware.

Home Depot carries both US-made 100 GPD systems and the review bodies on both pages carry iSpring's own attribution line against individual reviews, which makes these the two rows on the brand where the retailer pool is demonstrably partly the manufacturer's own file. Neither page publishes a readable star average or recommend rate, so there is no figure here to separate. Falling back to the brand's Home Depot record, where the readable figures are 98 percent recommend on the pumped RCC7 and 93 percent on the pooled tankless file.