ProOne Big+ Gravity Water Filter Review: Filters Contaminants and Microplastics in a 3-Gallon Gravity System

Where the Big+ Fits

ProOne Big+ Gravity Water Filter filters 3-gallon water for a household that needs a gravity filter with a 3-gallon capacity.

For an apartment counter, a 3-gallon gravity filter is the kind of size that can fit the space without looking oversized.

ProOne Big+ matches that scenario with a 3-gallon capacity and NSF/ANSI-42 certification. It also states stainless steel material, plus a stainless steel spigot and stand.

We screened 28 Gravity Water Filters and this is one of 15 chosen for a full review. Full reviews go to the most-rated products that pass screening, at most 2 per brand. Big+ had 101 buyer ratings, the 13th most of the 28 screened. This review is for you if you want a gravity water filter for a compact setup and want the certified chlorine, taste, and odor baseline in view.

The Short Answer on the Big+

Best for: you want a 3-gallon gravity filter for a small kitchen, apartment counter, or RV setup.

Big+ is the right pick if you want stainless steel construction, a stainless steel spigot and stand, and NSF/ANSI-42 certified filtration for around $327.25.

• Pro: The 3-gallon capacity gives you enough stored water for a small household without constant refills.
• Pro: Stainless steel construction, plus the included spigot and stand, gives you a full countertop setup in one package.
• Pro: NSF/ANSI-42 certification covers chlorine, taste, and odor claims, and the listing also says it removes contaminants and microplastics.
• Con: A 3-gallon tank is short of the larger batch size that reduces refills for higher daily use, so heavy-drinking households will refill more often.
• Con: The $327.25 price is a high entry point for a gravity filter, which makes this a harder buy if your budget is tight.

Don’t buy this if: you need a gravity filter that can hold 3.25 gallons or more for higher daily use.

Price assessment: Premium for the capacity and included stainless steel parts.

If you need a smaller footprint, you can view our full CO-Z Gravity Filter review.

Residents with limited space should see the best gravity water filter for apartments.

The Specifications That Matter for this Gravity Water Filter

Capacity most separates the Big+ here. Capacity measures how much water the filter holds at one time, which affects refill frequency.

Before You Buy: Gravity Water Filter Checklist

The first thing to check is countertop space, because Big+ states a 3-gallon capacity and includes a stand, so it needs room for a full gravity setup.

• ☐ Confirm your counter can hold a 3-gallon gravity filter with its stand — otherwise you may end up moving it off the kitchen counter or returning it unused.
• ☐ Check that you want a stainless steel body and stainless steel spigot — if you expected plastic parts, you will need to accept the metal build or choose another model.
• ☐ Budget for the $327.25 price — if that amount is too high for a 3-gallon unit, this purchase will strain the budget without solving the capacity need.
• ☐ Confirm the NSF/ANSI-42 certification is the level you need — if you need a different contaminant claim, you may have to return it and buy a different filter.
• ☐ Check that the included faucet and stand suit your setup — if either piece does not fit your space, you will need to modify the layout or replace the unit.

Do not buy Big+ if you need a larger batch size for heavier daily use, because its 3-gallon capacity is not the larger countertop class.

Performance: What the Specs Deliver

How Contaminant Reduction Fits a 3-Gallon Gravity Filter

Big+ gives you a 3-gallon hold, so you can keep a small household supply ready without constant topping up. That size suits a countertop gravity filter for a short family dinner or a compact kitchen, but it is short of a full day for heavy drinking and cooking.

Big+ states NSF/ANSI-42 certification, and the listing also says it removes contaminants and microplastics. That combination addresses common tap concerns, while the silver-infused filters are there to limit contaminant growth during regular use. If you skip that level of contaminant reduction, you may pay for a rebuild later because the unit will not match the water-quality problem you meant to solve.

How Mineral Retention Works in this Countertop Gravity Filter

Big+ retains minerals such as calcium, so your filtered water keeps the minerals this kind of system is meant to leave in place. That matters if you want contaminant reduction without stripping the water down to a blank slate.

The mineral-retention claim pairs with the 3-gallon capacity to make the unit more useful for everyday drinking than for large-batch storage. Big+ is a fit when you want filtered water ready on the counter and still want the water to keep its mineral profile, but it does not turn a 3-gallon tank into a larger reserve.

Why a Stainless Steel Gravity Filter Suits Countertop and RV Use

Big+ is a gravity filter with a stainless steel body, a stainless steel spigot, and a stainless steel stand. That setup suits countertop and RV use because it gives you a self-contained system that does not need power and still has a fixed place on the counter.

The included faucet and stand make the 3-gallon format easier to place and dispense from than a bare chamber setup. Big+ works for a small apartment counter or a trip in an RV, but the same capacity will not cover a full day of home drinking and cooking for a high-use household.

The Big+ Job by Job: What Its Figures Cover

The Big+ against the jobs buyers ask about, worked out from its listed capacity and a typical need for each job.

How the Big+ Compares to Other Gravity Filters

Big+ has the largest stated capacity in this comparison at 3 gallons, and it does so while listing a $327.25 price. That pairing gives you more stored water than the smaller 2.25-gallon and 2.75-gallon rivals without moving into the higher $367 and $408 price tiers.

• Against the Berkey BB9-2 Water Filter System, Big+ gives you 3 gallons instead of 2.25 gallons. That extra stored volume matters more than the small price gap if you want fewer refills.
• Against the Berkey Light Gravity-Fed Water Filter System, Big+ keeps the same stainless steel build but adds more capacity. The 2.75-gallon Berkey Light is still smaller, so Big+ is the better fit when batch size matters more than brand familiarity.
• Against the Berkey Travel Water Filter, Big+ is $80.75 cheaper. The Travel model is the pricier option if you want the portability angle and are willing to pay for it.
• Against the FACHIOO Gravity-Fed Water Filter System, Big+ includes a stainless steel stand and a stainless steel spigot material listing. FACHIOO is cheaper at $199.99, so that is the more budget-focused pick.
• Against the Waterdrop WD-TK-A-FS, Big+ has the stronger buyer-rating position in this set, with a 4.0 average from 101 ratings. Waterdrop is also rated 4.0, so the difference is not in score but in the larger 3-gallon capacity here.

If you want the lowest upfront price, FACHIOO is the better pick. If you want the biggest stated reservoir in this group, Big+ is the one to choose.

For a different design, look into the KST-XYB101 spec breakdown.

Consider exploring the alternatives to a gravity water filter if these options don’t fit your needs.

From Delivery to First Use with This Gravity Filter

Get Big+ ready to use

A countertop surface and the stainless steel stand are the first things Big+ needs before it can do anything useful.

1. Unpack the 3-gallon gravity filter and place the stainless steel stand on a level countertop.
2. Set the polished stainless steel chambers onto the stand and align the spigot opening at the front.
3. Fit the stainless steel spigot and gasket together so the outlet seals before you add water.
4. Install the ProOne G2.0 filter element, and use the priming washer if the element style you receive needs it for setup.
5. Fill the upper chamber, then let gravity move the water through the NSF/ANSI-42 certified filter before first use.

Warranty and support: what to check for Big+

Cover varies by seller and country.

• Confirm the replacement filter element match, because the G2.0 element is the part that keeps filtration going after the first months of use.
• Confirm the spigot gasket size and fit, because the stainless steel spigot is the outlet part most tied to leak risk.
• Confirm whether a priming washer is included or sold separately, because some filter elements need it before they will run correctly.
• Confirm whether a fluoride filter element is supported for this model, because that extra reduction stage is a separate purchase and not stated as included.

On the day it arrives, inspect the spigot, stand, and filter element together before the return window closes.

The Big+: Remaining Questions

How long does one filter really last if I use it every day?

Big+ uses a ProOne G2.0 filter that lasts up to 9 months with regular daily use. That figure gives you a replacement window, not a guarantee of the same interval for every household. If you filter heavily every day, plan around the 9-month mark and treat earlier replacement as a possibility.

Is it worth the price for what you get, or am I paying extra for the stainless look?

The $327.25 price buys a 3-gallon stainless steel gravity filter with a stainless steel spigot, a stainless steel stand, and NSF/ANSI-42 certification. The stainless build is not the only thing in the price, because the listing also states a filter that removes contaminants and microplastics while retaining minerals such as calcium. If you want a countertop system with those stated parts and that capacity, the price is tied to more than appearance alone.

Is the Big+ Right for You?

Who the Big+ suits and the jobs it is the wrong choice for, listed below with the reason for each.

Where to Buy This Gravity Water Filter

Gravity water filters are sold by the retailers below – we do not track which of them has the Big+ in stock, so check availability and the current price with the retailer before making a trip.

• REI (online and physical stores) — specialist staff and trusted outdoor-water-filter selection
• Bass Pro Shops (online and physical stores) — specialist staff for camping and emergency water filtration
• The Berkey Store (online only) — specialist retailer for gravity water filters
• Amazon (online only) — breadth of range
• Walmart (online and physical stores) — in-store returns
• Target (online and physical stores) — easy local pickup and returns
• Home Depot (online and physical stores) — in-store returns and broad household category coverage

Final Verdict on the Big+

You need a 3-gallon gravity water filter for a small kitchen or apartment counter, and the Big+ fits that use case at around $327.25.

What does that buy you here? A stainless steel body, a stainless steel spigot, and an included stand, plus NSF/ANSI-42 certification and a 4.0 average from 101 buyer ratings.

Skip it if: you need enough capacity for a full day of heavy home drinking or a weekend outage, or you want a larger batch size than 3 gallons.