Distilled water is one of the most reliable household essentials you can keep on hand, yet knowing where to find it and what to look for before you buy can save you both money and hassle. Whether you need it for a CPAP machine, a steam iron, a car battery, or a home aquarium, this type of purified water is widely available at grocery stores, pharmacies, and major online retailers. This guide covers everything from the best places to buy distilled water to the features that matter most, common purchasing mistakes, and top product picks worth considering. We also answer the most frequently asked questions about this essential product, including whether it is safe to drink and how long it lasts once opened.
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What Is Distilled Water and Who Needs It
Distilled water is H2O that has been purified through a steam-based process. Ordinary tap water is heated until it evaporates. The rising steam leaves behind dissolved minerals, chemicals, and impurities. It is then collected and condensed back into liquid form, producing a product that is virtually free of calcium, magnesium, fluoride, chlorine, and other contaminants found in municipal supplies.
People who use CPAP machines for sleep apnea rely on this purified product to keep the humidifier chamber free of mineral buildup. Hobbyists use it in aquariums and fish tanks to maintain proper chemistry. It is also the preferred choice for steam irons, car batteries, and certain laboratory or cosmetic applications. Anyone who needs an ultra-pure liquid without additives or naturally occurring minerals will benefit from keeping a gallon or two at home.
What to Look For: Features and Buying Criteria
Purity level. Genuine distilled products should contain fewer than 10 parts per million of total dissolved solids. Check the label for terms like “purified by distillation” rather than just “purified,” which may use reverse osmosis or filtration instead. The steam-based method removes a broader range of contaminants than standard filtration alone.
Container size. The most common option is the 1 gallon container, which is practical for most household uses and typically costs around a dollar. If you go through large volumes for a humidifier or respiratory device, look for multi-packs to save per unit.
Packaging material. Most options come in plastic containers or jugs. If you are concerned about chemicals leaching from plastic, look for BPA-free packaging or consider using a home distillation unit that lets you store the finished product in glass.
Brand reputation. Store brands like Great Value from Walmart and Good & Gather from Target offer reliable distilled water at the lowest prices. National brands such as Smartwater and Aquafina are more widely recognized but often cost more per ounce. For most applications, a generic store-brand gallon performs identically to premium options.
Intended use. If you plan to use distilled water in a CPAP humidifier or for mixing baby formula, confirm the label states it meets drinking standards. Products labeled for automotive or industrial use may not carry the same safety certifications. Always match the product to its intended purpose before making a purchase.
What to Avoid When Buying Distilled Water
Confusing purified water with the distilled variety. These two products are not always the same thing. Purified products can be processed through reverse osmosis, deionized filtration, or other methods that may not remove all the same substances that boiling and condensing does. If your device specifically requires the distilled variety, read the label carefully.
Grabbing flavored or enhanced products by mistake. Some retailers shelve enhanced or electrolyte-added options right next to plain distilled ones. Additives and minerals defeat the purpose, especially in a respiratory device or steam iron where mineral-free purity is critical.
Ignoring expiration dates. Once opened, this product can absorb carbon dioxide and other gases from the air, which lowers its purity over time. Use opened containers within one to two weeks, and store sealed containers in a cool, dark place away from chemicals or solvents. Keeping the cap tightly closed between uses helps prevent contamination from airborne particles.
Overpaying for small sizes. Buying a single-serve container costs far more per ounce than a standard gallon. Unless you need a small, portable amount for travel, the larger size is almost always the better value.
Where to Buy Distilled Water In Store
Walmart
Walmart stocks its own Great Value brand in the beverage aisle, usually for under a dollar per gallon. Some locations also carry name-brand options and multi-packs. Availability can vary by store, but the Great Value gallon is one of the most affordable options anywhere. Browse their selection online to check local stock before visiting.
Target
Target sells its Good & Gather store-brand option starting around a dollar per gallon. You can order online for same-day store pickup, which is convenient when you need it quickly. Shipping is also available on orders over twenty-five dollars. The product is usually located in the beverage aisle alongside other purified and spring options. Check their current listings to see what sizes and brands your local store carries.
Walgreens
Walgreens carries this product in most locations, typically in the beverage or health care aisle. Their Nice! store brand offers a gallon-size option, and you may also find Smartwater or other brands in smaller sizes. Selection varies by location, so call ahead if you need a specific size or brand. Check the Walgreens website for availability near you.
Local Grocery Stores
Nearly every grocery store stocks this product in the beverage section. Brands and pricing vary, but most store-brand gallons sell for around a dollar. Stores that participate in loyalty reward programs may occasionally offer coupons or discounts. Because this product is heavy relative to its price, buying locally saves you shipping costs compared to ordering online. Most locations keep gallon sizes on lower shelves, so check near the bottom of the beverage aisle if you do not see them right away.
CVS and Other Pharmacies
Many pharmacy chains stock gallon containers near the health care supplies or personal care aisles. CVS, Rite Aid, and independent pharmacies often carry at least one brand. Prices may be slightly higher than at grocery stores, but the convenience of a nearby pharmacy makes it a practical option when you need a quick refill for a respiratory device or neti pot. If you use a CPAP machine nightly, keeping an extra gallon from a pharmacy close to home means you never run out unexpectedly.
Where to Buy Distilled Water Online
Amazon
Shop on Amazon #ad to find single gallons, multi-packs, and even home distillers that let you make your own supply. Prices vary widely depending on the brand and pack size. Subscribe and Save options can lower the per-unit cost if you go through this product regularly. Read reviews carefully, as some listings include filtered or spring varieties mixed into the search results.
Other Online Options
Beyond Amazon, you can order from Walmart.com, Target.com, and pharmacy sites like Walgreens.com for delivery or store pickup. Specialty retailers also sell larger volumes, such as five-gallon containers, for commercial or medical use. If you consume large quantities regularly, a countertop distiller is a practical long-term investment that pays for itself over several months of buying pre-packaged supply.
Top Picks
Best budget: Great Value Distilled Water (1 Gallon). Walmart’s store brand offers reliable purity at under a dollar per gallon. It works well for respiratory devices, irons, and car batteries. Hard to beat on price for everyday use, and it is available at nearly every Walmart location nationwide.
Best overall: Good & Gather Distilled Water (1 Gallon). Target’s house brand is consistently available in store and online. Same quality as premium brands at a fraction of the cost. Around one dollar per gallon. A solid all-around pick for most household needs.
Best for portability: Smartwater Vapor Distilled Premium. Available in convenient single-serve sizes, Smartwater is easy to find at pharmacies, gas stations, and grocery stores. Expect to pay around one to two dollars per serving, but the portability is worth it when you need a clean option on the go.
Best for making your own: Megahome Countertop Distiller. If you consume this product daily, a home distiller produces about one gallon every five to six hours. Priced around eighty to one hundred and fifty dollars, it eliminates ongoing purchases. Ideal for long-term users who rely on pure H2O for health equipment or household appliances. The machine also comes with activated carbon sachets to polish the final product.
Frequently Asked Questions
Can you drink distilled water?
Yes, distilled water is safe to drink. It simply lacks the minerals found in regular tap water, such as calcium and magnesium. Consuming it occasionally is perfectly fine, though relying on it as your only source long-term may mean you need to get those minerals from food or supplements.
Is distilled water the same as purified water?
Not exactly. Distilled water is one type of purified product, but not all purified options are made through distillation. Purification can involve reverse osmosis, carbon filtration, or deionized methods. The steam-based process specifically involves boiling, capturing the rising gas, and condensing it back into liquid, which removes a very broad range of impurities.
Why is distilled water recommended for CPAP machines?
Manufacturers recommend it because the process removes mineral content that would otherwise build up inside the chamber. Tap water or even filtered alternatives can leave behind calcium and other residues that create hard scale buildup, which can harbor bacteria and shorten the life of the equipment. Using a mineral-free option keeps the device clean and functioning properly.
Does distilled water expire?
Sealed containers do not truly expire, but the contents can absorb gases from the packaging over time. Most manufacturers print a best-by date for quality purposes. Once opened, use the product within a week or two and keep it sealed between uses to maintain purity.
Where is distilled water in the grocery store?
Look in the beverage aisle, usually on the bottom shelf near the gallon sizes. Some stores place it near the baby supplies or pharmacy section. If you cannot find it, ask an employee for help locating it — nearly every major grocery chain in the country carries at least one brand.
Our Editorial Process
Reviewed by the wheretobuyguides.com editorial team. Our writers research product availability across major retailers and verify pricing and stock details before publishing. Last updated: March 2026.
Whether you pick up a gallon at your local grocery store or order a case of distilled water online, the right product is easy to find once you know where to look and what to watch out for. Check our other household product guides for more buying tips.