How to Fill a Kitchen Sink With Water: Choosing the Right Sink Stopper for Washing and Soaking

By Kevin Cody | Founder & CEO, FLI Products / Mary Joan Isorena, Communications
Published: September 21, 2026

Need to fill your kitchen sink with water for soaking or hand-washing? The right kitchen sink stopper needs to hold water when you need it and let the sink return to normal draining afterward. A 2-in-1 option such as Flex Strainer® combines stopping and everyday straining in one product, so you don't need to keep switching between separate sink accessories.

Whether you're soaking cookware, hand-washing dishes or simply need a basin of water for a kitchen task, understanding the difference between a sink strainer and a sink stopper can help you choose the right setup for your drain.

Visit the Flex Strainer hub for more kitchen sink care, drain protection, and product guidance.

Key Takeaways

• A kitchen sink stopper closes the drain so the basin can hold water.

• A sink strainer allows water to drain while catching food scraps and solid debris.

• Before buying a replacement stopper, check the size and configuration of your drain rather than assuming every product will fit.

• Flex Strainer® 2-in-1 Sink Strainer & Stopper combines both functions in one flexible product.

• Flex Strainer is designed to fit most standard 3.5-inch kitchen sink drains and garbage disposals and measures 5.25 inches across.

• When you want to hold water, use the stopping function. When you're ready for normal sink use, return it to straining mode.

• A stopper cannot repair a damaged drain assembly or another plumbing problem that prevents the sink from holding water.

The basic idea is simple:

STRAIN FOR EVERYDAY USE → STOP TO HOLD WATER → SOAK OR WASH → RETURN TO STRAINING

Why Would You Need to Fill a Kitchen Sink With Water?

For much of the day, a kitchen sink needs to do one thing particularly well: drain.

Turn on the faucet, rinse something and the water leaves the basin.

But some kitchen tasks require exactly the opposite.

You may want to fill the sink to soak cookware before cleaning it, hand-wash dishes or complete another task that requires standing water.

At that point, the drain needs to be temporarily closed.

That's the job of a sink stopper.

The challenge is that once you're finished holding water, you need the sink to go back to normal draining—and during normal kitchen use, you may also want something at the drain opening that catches solid food debris.

That is where understanding the difference between a stopper and a strainer becomes useful.

Sink Strainer vs. Sink Stopper: What's the Difference?

Although both sit at or around the kitchen drain, they perform different jobs.

A Sink Strainer Lets Water Through

A kitchen sink strainer is designed to allow water to drain while intercepting food scraps and other solid debris at the drain opening.

Water goes through.

Larger solids stay behind so they can be removed and disposed of rather than deliberately washed into the drain.

A Sink Stopper Holds Water In

A sink stopper does the opposite.

Instead of allowing water to continue through the drain, it closes the opening so water remains in the sink basin.

That's useful when you want to fill the sink rather than continuously drain it.

So the two jobs are:

STRAINER = LET WATER OUT + CATCH SOLIDS

STOPPER = KEEP WATER IN

Traditionally, that can mean keeping two separate accessories around the sink.

But it doesn't have to.

Do You Need a Separate Sink Strainer and Stopper?

Not necessarily.

If your sink setup uses separate accessories, you may remove the strainer when you want to stop the drain, install the stopper, fill the sink and then reverse the process when you're finished.

That works.

But if you regularly use both functions, a product that combines straining and stopping can simplify what stays around the drain.

That's the specific problem the Flex Strainer® 2-in-1 Sink Strainer & Stopper is designed to address.

Instead of being a dedicated basket strainer like the Flex Strainer Basket featured in our drain-care articles, this Flex Strainer model combines everyday straining with an optional sink-stopping function in one design.

How Flex Strainer® Combines Straining and Stopping

During normal kitchen use, Flex Strainer can function as a strainer at the drain opening, catching food scraps and debris while allowing water to drain.

When you need the sink to hold water, the same product can be used in its stopping function.

That creates a simple workflow:

Normal Sink Use

STRAIN

Water drains while Flex Strainer catches solid debris.

Need to Fill the Sink?

STOP

Use the stopping function so the sink can hold water.

Washing or Soaking

HOLD WATER

Use the filled sink for the task at hand.

Finished?

RETURN TO STRAINING

Release the water and return Flex Strainer to its everyday straining function.

The current FLI product page describes Flex Strainer as a 2-in-1 strainer and stopper designed for these two jobs.

Shop Flex Strainer® 2-in-1 Sink Strainer & Stopper

Check Your Kitchen Drain Size Before Choosing a Stopper

A sink stopper only makes sense if it is appropriate for the drain where you plan to use it.

Don't choose one based only on how it looks.

Check your sink and the product's stated fit specifications first.

For Flex Strainer specifically, FLI states that the 2-in-1 model:

• Fits most standard 3.5-inch kitchen sink drains and garbage disposals

• Measures 5.25 inches wide

• Combines straining and stopping functions

• Is flexible

• Is BPA-free

• Is dishwasher safe

• Is Made in USA

• Is available in black and gray

That makes the 3.5-inch drain specification particularly important when determining whether Flex Strainer is appropriate for your sink.

Not every drain configuration is necessarily identical, so verify your own sink rather than treating a general size description as a guarantee for every installation.

Filling the Sink for Soaking

One common reason to stop a kitchen drain is to soak dishes or cookware.

Instead of continuously running water, you may want to fill the basin and allow an item to sit in the water before continuing with cleanup.

With Flex Strainer, the stopping function provides the ability to hold water without keeping a completely separate stopper around the sink. FLI specifically identifies soaking and hand-washing among the intended uses of its 2-in-1 stopping function.

Once soaking is finished, the sink can return to its normal draining role.

And that's where the second half of the product becomes useful again.

Rather than replacing the stopper with another accessory, Flex Strainer can return to its straining function for everyday sink use.

What Happens When You're Ready to Drain the Sink?

Eventually, the water needs to leave.

Before draining a sink after washing or soaking, remove larger solid waste rather than intentionally sending it down the drain.

Then return Flex Strainer to its straining function as appropriate so water can drain while solid debris can be caught at the opening.

That follows the same principle we use throughout our Flex Strainer sink-care series:

Water belongs down the drain.

Solid food debris is better caught where it can still be removed and properly disposed of.

EPA homeowner guidance similarly advises keeping fats, oils and grease out of kitchen sinks and properly disposing of food waste rather than treating the drain as a general waste-disposal point.

Why a 2-in-1 Design Can Be Useful Around the Kitchen Sink

The advantage isn't that a separate stopper somehow cannot perform its job.

It can.

The difference is how many drain accessories you need to manage.

With separate products, your routine may look like:

STRAINER → REMOVE → FIND STOPPER → INSTALL STOPPER → FILL SINK → REMOVE STOPPER → REINSTALL STRAINER

A 2-in-1 product simplifies that relationship because the straining and stopping functions are built into the same sink accessory.

With Flex Strainer, the idea becomes:

STRAIN → STOP → HOLD WATER → DRAIN → STRAIN AGAIN

That's the actual differentiation of the product—not simply that it is another sink stopper.

Don't Confuse a Stopper Problem With a Plumbing Problem

There is an important limitation to understand.

If your kitchen sink will not hold water, the stopper isn't automatically the cause.

The drain assembly itself may have an issue, the drain configuration may not be appropriate for the stopper you're using, or another plumbing condition may be involved.

Similarly, if the sink drains slowly after you release the water, installing a different stopper doesn't remove an obstruction farther down the drain.

Flex Strainer is a sink strainer and stopper.

It should not be presented as a repair product for damaged plumbing or as a tool for clearing existing drain blockages.

If your actual problem is recurring clogging rather than holding water, our first article addresses that separately.

Read: Why Does My Kitchen Sink Keep Clogging? How to Catch Food Scraps Before They Go Down the Drain

And if you're looking for everyday preventive sink and drain habits:

Read: How to Take Care of Your Kitchen Sink Drain: Everyday Habits for Proper Drainage and Food-Waste Disposal

Replace these two links with the final Shopify URLs when the articles are published.

What About a Garbage Disposal Sink?

A kitchen sink with a garbage disposal can still need both straining and stopping functions.

FLI states that Flex Strainer is designed to fit most standard 3.5-inch kitchen sink drains and garbage disposals.

That means the product can provide a removable straining/stopping option at many standard disposal openings as well as standard kitchen drains.

However, Flex Strainer does not replace the operating instructions for your garbage disposal.

When the disposal itself is being used, follow the manufacturer's directions for that appliance.

Keeping Your Flex Strainer® Clean

Anything that regularly sits at a kitchen drain needs to be cleaned.

After using Flex Strainer for everyday straining, dispose of captured food scraps appropriately and rinse the product as needed.

FLI identifies the current Flex Strainer 2-in-1 as dishwasher safe, providing another cleaning option.

That gives the overall routine another straightforward step:

STRAIN → EMPTY → CLEAN

or, when you need to fill the sink:

STOP → SOAK/WASH → DRAIN → CLEAN → RETURN TO STRAINING

The goal is to keep the accessory ready for whichever job the sink needs next.

When Does the Flex Strainer® 2-in-1 Make Sense?

Consider the jobs you actually perform at your kitchen sink.

If you only need something that catches debris while water drains, a dedicated basket strainer may be enough.

FLI offers the Flex Strainer® Kitchen Sink Basket Strainer specifically for that purpose.

But if you want both everyday straining and the ability to stop the drain and fill the sink, the Flex Strainer 2-in-1 combines those two functions in one product.

That gives the two products distinct roles:

Flex Strainer Basket Strainer
→ Dedicated everyday straining and debris capture

Flex Strainer 2-in-1 Sink Strainer & Stopper
→ Everyday straining plus the ability to stop the drain when you need to hold water

Choosing between them comes down to what you actually need your sink accessory to do.

Shop Flex Strainer® 2-in-1 Sink Strainer & Stopper

Frequently Asked Questions About Kitchen Sink Stoppers

What can I use to stop my kitchen sink drain?

A kitchen sink stopper is designed to close the drain so the basin can hold water. Before choosing one, check the size and configuration of your drain and compare those measurements with the product's stated fit.

What's the difference between a sink strainer and a sink stopper?

A strainer allows water to drain while catching solid debris. A stopper closes the drain so water remains in the sink. Flex Strainer 2-in-1 combines both functions in one product.

Can one product be both a sink strainer and a stopper?

Yes. Flex Strainer is specifically designed as a 2-in-1 sink strainer and stopper, allowing it to serve different functions depending on whether you want the sink to drain or hold water.

What size drain does Flex Strainer fit?

FLI states that Flex Strainer fits most standard 3.5-inch kitchen sink drains and garbage disposals. The product itself measures 5.25 inches wide.

Can I use Flex Strainer to fill the sink for soaking dishes?

Yes. FLI identifies filling the sink for soaking and hand-washing as intended uses of the Flex Strainer 2-in-1's stopping function.

Can Flex Strainer be used with a garbage disposal?

FLI states that the 2-in-1 Flex Strainer fits most standard 3.5-inch kitchen sink drains and garbage disposals.

Is Flex Strainer dishwasher safe?

Yes. The current FLI product specifications identify Flex Strainer as dishwasher safe.

Is Flex Strainer Made in USA?

Yes. The current Flex Strainer 2-in-1 is Made in USA.

Will a new stopper fix a sink that still won't hold water?

Not necessarily. A stopper must fit and operate correctly, but problems with the drain assembly or other plumbing components can also affect whether a sink holds water. A sink accessory should not be treated as a repair for a separate plumbing problem.

One Sink Accessory, Two Everyday Jobs

Sometimes you need the kitchen sink to drain.

Sometimes you need it to do exactly the opposite.

That's why it helps to think about straining and stopping as two separate jobs.

For everyday cleanup, Flex Strainer® can allow water to drain while catching solid debris. When you need to fill the sink for soaking or hand-washing, the same 2-in-1 product provides the stopping function.

STRAIN WHEN YOU NEED TO DRAIN.

STOP WHEN YOU NEED TO HOLD WATER.

And when both jobs are part of your kitchen routine, you don't necessarily need two separate sink accessories to do them.

Shop Flex Strainer® 2-in-1 Sink Strainer & Stopper

About Kevin Cody

Kevin Cody | Founder & CEO, FLI Products

Kevin Cody is the Founder and CEO of FLI Products and a product development, merchandising and retail industry veteran with more than 20 years of experience. His background includes merchandising leadership at The Home Depot as well as developing, sourcing, manufacturing, marketing and bringing consumer products to market through major retailers and online marketplaces.

Kevin works directly with manufacturers, inventors, retailers and consumers to develop practical products that solve everyday problems. His experience spans product design and development, retail merchandising, manufacturing, e-commerce, marketplace strategy and consumer product education.

Through the FLI Products Learning Center, Kevin shares practical, experience-based information designed to help consumers better understand products, solve problems and make informed purchasing decisions.

Read Full Bio

About FLI Products

FLI Products develops and markets practical consumer products designed to solve everyday problems at home, outdoors and on the job. Working directly with manufacturers, inventors and retailers, FLI Products focuses on thoughtful product design, practical functionality and useful solutions for consumers. Its products are available through FLIProducts.com and select major retailers and online marketplaces.

About FLI Products

Sources & Resources

FLI Products — Flex Strainer® 2-in-1 Sink Strainer & Stopper
Current FLI specifications covering the product's 2-in-1 function, drain fit, dimensions, dishwasher-safe care and Made in USA origin.
View Flex Strainer® 2-in-1 Sink Strainer & Stopper

FLI Products — Flex Strainer® 3-Piece Set
Information about FLI's separate full-cover strainer, basket strainer and stopper configuration for standard 3.5-inch drains.
View the Flex Strainer® 3-Piece Set

U.S. Environmental Protection Agency — SepticSmart: Think at the Sink
EPA homeowner guidance covering what should stay out of kitchen sinks, including fats, oils and grease, and responsible food-waste disposal.
View EPA SepticSmart Guidance

Visit the Flex Strainer hub for more kitchen sink care, drain protection, and product guidance.