The Crystal Quest Classic Under Sink Water Filtration System is a point-of-use drinking water filter designed to install beneath a sink and supply filtered water through a dedicated faucet setup. It is available in Multistage Plus, Multistage Ultra, and Multistage Ultimate capacity options. Crystal Quest also offers separate under-sink specialty systems for concerns such as arsenic, fluoride, and nitrate removal, which should be selected as separate product types when those specific contaminants are the priority. The standard SMART Classic under-sink design uses six stages of filtration with one-micron filter pads, coconut shell granular activated carbon, ion exchange resin, Eagle Redox Alloy media, ceramic and tourmaline media, and final particle-reduction filtration. It has a listed 0.5 GPM maximum flow rate, 20–60 psi operating pressure, and compact 3.5" L × 10.5" H × 3.5" W housing. Follow the installation manual for faucet, connection, and pressure-related setup requirements.
This Crystal Quest Classic system is designed for point-of-use filtration beneath the sink rather than whole-house treatment. It keeps the filter housing out of sight while providing filtered water through the included faucet setup for drinking water and everyday point-of-use kitchen needs.
Water travels through one-micron filter pads, coconut shell granular activated carbon, ion exchange resin, Eagle Redox Alloy media, ceramic and tourmaline media, and final particle-reduction filtration. These stages are designed to help reduce listed impurities, taste, odor, and particles when present in the water.
Buyers can choose Multistage Plus, Multistage Ultra, and Multistage Ultimate capacity options for the Classic system. Separate Crystal Quest under-sink specialty systems are available for arsenic, fluoride, nitrate removal, and other targeted drinking water concerns.
The system uses standard 1/4" connections, with a 3/8" conversion package available when needed. The installation manual should be checked before setup to confirm the correct valve, faucet, and connection requirements for the home’s under-sink plumbing.
This compact under-sink filter is built for households that want filtered drinking water without a countertop unit. It installs below the sink and pairs with a faucet setup for filtered water access at the sink.
Choose the filter type and connection option that match your water concerns and plumbing. Capacity, specialty contaminant focus, and valve selection should be confirmed before installation.
Need help choosing an under-sink filter option?
TrueStead Supply can help you compare capacity, specialty cartridge type, and installation requirements.
✓ 10,000-30,000 gallon capacity options
✓ Six-stage SMART Classic filtration
✓ Under-sink drinking water setup
| Brand | Crystal Quest |
| Product Type | Classic under sink water filtration system |
| Installation Type | Under sink, faucet setup |
| Filtration Stages | 6 stages |
| Filter Options | Multistage Plus, Multistage Ultra, and Multistage Ultimate capacity options |
| Multistage Plus Capacity | 10,000 gallons |
| Multistage Ultra Capacity | 20,000 gallons |
| Multistage Ultimate Capacity | 30,000 gallons |
| Max Flow Rate | 0.5 GPM |
| Suggested Flow Rate | 0.5 GPM or less |
| Operating Pressure | 20-60 psi |
| Operating Temperature | 40°F-90°F |
| Connections | Standard 1/4"; 3/8" conversion package available if needed |
| Faucet / Installation Note | Follow the installation manual for faucet, valve, connection, and pressure-related setup requirements |
| Dimensions | 3.5" L × 10.5" H × 3.5" W |
| Listed Product Attributes | BPA-free, ISO-certified, made in the USA |
| Water Source Requirement | Use on cold potable water; follow the installation manual and local plumbing codes before setup. |
