Carpets get mucked up for a variety of reasons – foot traffic, pet accidents, spills, children – and a carpet cleaning machine is the number one way to remove stains. You can either own or rent these cleaners to keep your carpet fresh, but they simply won’t work without a carpet cleaning solution.

When it comes to shampooing your carpet, the solution you use in your cleaner is more important than you might think. Budget-minded folks may try to cut corners on the carpet cleaning solution by using a cheaper brand or using less than the recommended amount, but if you want your carpet to get clean and be stain- and odor-free, you need to use the right amount of the right solution.

There are quite a few varieties on the market, so choosing the best one for your needs can be tough. Your preference for a strong or mild scent is a factor, or you  might need one that’s safe for pets and/or children. Whatever your need, we’ve got you covered. Take a look at our top recommendations if you’re ready to buy, or read our shopping guide below for a deeper dive into all you need to know about carpet cleaning solution.

How carpet cleaning solution works

Carpet cleaning solution is designed to be used with a carpet cleaning machine to yield professional-grade results without having to hire someone to do the (often costly) job for you. These machines have a tank in which to mix the solution with water or a separate reservoir to hold the solution. Both the water and solution come out the brush head as you move the unit over the carpet in a vacuuming motion. Often the solution lathers like shampoo, which is why cleaners are also referred to as carpet “shampooers.”

Types

Carpet cleaning solution comes in three formulas.

• Traditional: Conventional carpet cleaning solution often contains chemicals to effectively clean carpets. These formulas tend to come from major brands and are designed for use with the company’s carpet cleaning machines. These powerful detergents can leave behind a strong artificial scent that isn’t ideal for those who are sensitive to fragrance. However, some brands are shifting to safer, less toxic, and more biodegradable ingredients. Though not the greenest option on the market, they are markedly safer for pets, children, and the environment.

• Enzymatic: This type of cleaning solution utilizes enzymes to “eat away” at stains and odor. Enzymes are biological compounds that break down organic matter. They work particularly well on pet messes while also being safe for pets and the environment. Another bonus is that they can be found at entry-level prices, unlike other green products. A drawback is that enzymes require patience because the solution must be left to dry completely in order to work effectively, and sometimes the cleaner emits a smell that gets worse before it gets better.

• Green: This type of carpet cleaning solution is made from nontoxic and often plant-based ingredients. The formulas contain no harsh chemicals and the scents tend to be less of an irritant, if not hypoallergenic. Green carpet cleaning solution is safe for the entire household, including pets. However, these formulas tend to cost much more than traditional detergents.

Concentration: Similar to laundry detergent, carpet cleaning solution comes in formulas of various concentration, typically double the strength, meaning you use half the amount for the same result. The biggest benefit of a concentrated solution is that you get more bang for your buck because the bottle lasts longer. The only drawback is that you have to be careful not to use more than the recommended amount or your machine could produce too much foam.

Odor remover/deodorizer: In tandem with stain-removing properties, a lot of the formulas on the market also come with odor-removing ingredients. A solution that contains enzymes is particularly useful for eliminating odors because it actually breaks down the odor-causing particles rather than mask them with scent.

Pet: Some carpet cleaning solution is marketed as better for households with pets. However, a high-quality product should work just as effectively on pet stains as other stains whether it’s specified for pets or not. You might not need to spend the extra bucks on a pet-formulated solution.

Upholstery: An added benefit of some formulas is that they can be used to clean water-safe upholstery. Dilute the solution in a bucket of warm water and use either a cloth or upholstery brush to clean rugs, couches, curtains, car interiors, or other fabric upholstery.

Spot treatment: Some solution also works to pretreat stains. Spot-clean by hand following the instructions on the container.

Scent: The strength and type of scent vary with these products. Some consumers prefer the fragrance offered by traditional detergents, which they associate with a “clean” carpet. Other people prefer minimal scent, especially those with a sensitivity to fragrance. Green products tend to offer milder scents that are less likely to trigger allergic reactions.

There are a few factors that determine the price of a carpet cleaning solution: bottle size (which can range from 25 ounces to a gallon), concentration, and type.

Traditional

These detergents are priced from $7 to $25, although a lot of them have double the concentration, so you should factor that into the price.

Enzymatic

These formulas can be found at a bargain price of $7 to $20 for a gallon.

Green

These tend to be the priciest at $15 to $30 for a bottle of 25 or 32 ounces.

• Vacuum the carpet first. Before using a cleaner, it’s a good idea to vacuum the carpet to remove debris and pet hair.

• Test a small patch of your carpet for colorfastness. Do this before using the cleaning solution on the whole carpet.

• Shake enzymatic cleaner before using. If using a carpet cleaning solution that contains enzymes, always shake the bottle first to activate the enzymes.

• Rinse the carpet with water. After cleaning your carpet using the carpet cleaning solution and machine, make another pass over it with just water to make sure all the detergent is rinsed out of the carpet fibers.

• Treat stains as soon as they happen or within the first few days. This gives you the best chance at removing them. Knowing how to clean and pretreat stains will help you get the most out of your carpet cleaner and the solution you use.

Though not all formulas of carpet cleaning solution are created equal, there are a lot of good ones on the market. There is a whole subcategory designed for pet stains, and some even specifically target urine stains.The Bissell 2X Pet Stain and Odor Full Size Machine Formula is a top seller and rivals our Best of the Best choice. Pet owners swear by this “miracle” solution to eliminate pet stains and bad smells. We particularly love that it dissuades pets from remarking the spot. Another popular detergent formula for pets is Bubba’s Super Steamer Carpet Cleaner. This third-party brand is compatible with Hoover and Bissell cleaners and has the added value of working on upholstery, too. The minty-scented solution exceeds expectations in removing old pet stains, and we love that it has a 100% money-back guarantee.

Q. My carpet cleaner specifies using its brand of solution. Can I use other brands with it?

A. Yes and no. A number of machines specify in the instructions that the warranty is invalidated if you don’t use its solution with its cleaner. However, these warranties only last a few years, so you’re free after that to change formula as long as it’s designed for use in a carpet cleaning machine.

Q. My cleaner has a separate compartment for detergent and I’m using a concentrated solution. Do I need to dilute it first?

A. If you’re using a cleaner that doesn’t have a single tank for water plus solution, we’d recommend diluting the concentrate one part detergent to four parts water. In tanks that have a detergent line marked, you’ll also need to adjust the amount. We suggest contacting the manufacturer or looking on its website to find out how much concentrate to use.

Q. Do I put hot or cold water in my cleaner?

A. Hot water speeds up chemical processes and also helps dissolve dirt, so we recommend using hot water with detergent carpet cleaning solution. Please note that if you’re using a cold water extraction cleaner, only use cold water as instructed.