
Big Berkey 2.25 Gallon
Score: 78/100
APEC RO-CTOP
Score: 75/100Rankings

The Big Berkey is a gravity-fed countertop water filtration system constructed from surgical-grade stainless steel, designed to remove over 200 contaminants without requiring electricity. Its main limitation is the slow filtration speed and lack of official NSF certification for the complete system. It is best suited for small households, off-grid living, and emergency preparedness.

The APEC RO-CTOP is a portable, countertop reverse osmosis system that produces up to 90 gallons per day of purified water without requiring permanent installation. It features a 4-stage filtration process using US-made components and connects directly to standard kitchen faucets. Ideal for renters and travelers, though it lacks a storage tank and has faucet compatibility limitations.
| Attribute | ![]() | ![]() |
|---|---|---|
0.06 GPM | 0.063 GPMbest | |
60 monthsbest | 12 months | |
2 stages | 4 stagesbest | |
— | 99 %best | |
| ↓ lower better | 0 PSIbest | 30 PSI |
| ↓ lower better | 0.2 micronsbest | 5 microns |
| ↓ lower better | 1 ratiobest | 2 ratio |
0.5 years | 1 yearsbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Installation & Compatibility(1) | ||
Operating Pressure (PSI) | 0 PSI | 30 PSI |
Filtration & Performance(6) | ||
Filtration Technology | Gravity | Reverse Osmosis |
Flow Rate (GPM) | 0.06 GPM | 0.0625 GPM |
Filtration Stages (stages) | 2 stages | 4 stages |
TDS Reduction (%) | null % | 99 % |
Micron Rating (microns) | 0.2 microns | 5 microns |
Pure to Drain Ratio (ratio) | 1 ratio | 2 ratio |
Maintenance & Warranty(2) | ||
Filter Lifespan (months) | 60 months | 12 months |
Warranty (years) | 0.5 years | 1 years |
Dimensions & Build(3) | ||
Height (inches) | 21 inches | 6.5 inches |
Width (inches) | 8.5 inches | 6.0 inches |
Depth (inches) | 8.5 inches | 14.0 inches |


Products in the top-left offer the best value (high score, low price).

Professional reviewers and editors praise the Big Berkey for its robust contaminant removal capabilities, noting that it exceeds NSF/ANSI Standard 53 in laboratory settings. Experts highlight its durable stainless steel build and versatility for various water sources. However, they criticize the slow filtration flow rates and the lack of official NSF certification for the complete system.
Everyday users generally praise the Big Berkey for its reliability, long filter life, and ability to purify water without electricity, making it a favorite for families and emergency preparedness. Common recurring complaints include the slow filtration speed, which can take over two hours to fill, and the hassle involved in priming the filters.

Professional reviewers emphasize the RO-CTOP's exceptional value for portability and high water output, noting its 90 GPD capacity is among the highest recommended for portable units. The system's water efficiency is praised for outperforming the average fixed installation system's waste ratio.
Everyday users frequently praise the ease of setup, portability, and the significant improvement in water taste for coffee and tea. Recurring complaints focus on incompatibility with modern pull-out faucets and frustration with slow production rates at low water pressures.

