What this under-sink filter does for your kitchen
- Before bringing it home: check that your under-sink cabinet has room for the system and a standard sink setup for a dedicated faucet.
- Confirm the incoming water line and the faucet hole before you cut or drill anything.
The iSpring PH100 is a six-stage under-sink reverse osmosis system that produces up to 100 gallons per day. It's designed for households that want cleaner drinking water without relying on bottled water for daily glasses, coffee, ice, or formula.
The sixth stage is an alkaline remineralization filter, which restores minerals that the RO membrane removes. The included brushed nickel faucet gives you a dedicated tap at the sink.
We'd consider this a strong fit if your household already uses bottled water regularly and wants a fixed supply under the sink. The 100 GPD flow rate and 1:1 pure-to-waste ratio mean fewer refill trips and less wastewater than many older RO systems.
What the $305.98 price means
At $305.98, the iSpring PH100 sits below its typical price over the last 90 days. That figure is the typical price over the last 90 days for this model, not a one-day sale.
The system includes US-made filters and a manufacturer support line based in Atlanta, Georgia. Replacement filters are available under the F9KUS and F19K100US model codes. Planning for those replacements is part of the long-term cost.
| Offer detail | Recorded value |
|---|---|
| Amazon price | $305.98 |
| Customer rating | 4.5 |
| Customer reviews | 339 |
| Typical price over 90 days | $349.53 |
| Difference | $43.55 (12 percent) |
Room fit, filter changes and upkeep
The system fits under a standard kitchen sink and uses 3/8-inch quick-connect fittings for input and output. Installation is designed for DIY with push-to-connect tubing and included tools, though you'll want to confirm your cabinet height and depth before ordering.
Filter changes are part of ownership. The manual and installation videos walk through the process, and the clear first-stage housing lets you see when that filter needs attention. Replacement filter costs aren't listed here, so check current pricing for the F9KUS and F19K100US filters before you commit to the system.
The faucet is brushed nickel and all-metal. Cleaning is straightforward, but check whether your sink already has an unused hole for a dedicated drinking-water tap.
When the iSpring PH100 is the wrong fit
Skip this if you need a system that connects to your existing refrigerator ice maker without extra parts. The listing points to a separate ice maker water line kit, so factor that in if chilled water or ice is the main goal.
You should also skip it if you're not prepared to change filters on schedule or if under-sink space is very tight. A whole-home filter or countertop pitcher may suit you better if you don't want a dedicated faucet or routine filter swaps.
Product details
| Model | PH100 |
|---|---|
| Color | White |
