FAQ

Will this fit my shower?

Very likely. All three filters fit a standard ½-inch shower arm, which GoodFor says covers the vast majority of US showers. To check yours, unscrew the shower head and look at the threaded end of the arm. The GoodFor filter also works with handheld and rain heads. The Sentry filter is the largest and needs about 5 in wide × 12 in tall of space. If you're unsure, contact us with a photo of your shower arm.

What does the filter reduce?

It depends on the model. Crystal Quest's cartridge (CQE-RC-04045) was tested by QFT Laboratory to NSF/ANSI 177 for chlorine reduction and measured about 72 to 89 percent under the test conditions shown on its product page. That is a test report, not a certification. Sentry and GoodFor haven't shared model-specific test results with us, so we don't list filtration claims for those models.

Is a shower filter the same as a water softener?

No. Filtration and softening are different functions; water hardness comes mainly from dissolved calcium and magnesium. Crystal Quest and GoodFor both state that their shower filters do not soften hard water.

Will it change my skin or hair?

We recommend choosing a filter based on its documented function and compatibility. Individual experiences with hair and skin vary, and a shower filter isn't a treatment for any medical condition.

How often should I replace the cartridge?

Follow your model's guidance. Crystal Quest recommends a new cartridge every 6 to 12 months, or sooner if flow drops or a chlorine smell returns. Sentry recommends a new filter once a year for one shower a day, or every 6 months for two or more. GoodFor recommends a new cartridge every 90 days; it lasts 3 to 6 months.

Which replacement cartridge do I need?

Choose the cartridge listed as compatible with your filter: the Sentry Shower Replacement Filter for the Sentry Shower Filter, the Crystal Quest cartridge CQE-RC-04045 for the Crystal Quest Shower Filter, and GoodFor Shower Filter Replacement Cartridges for the GoodFor 8-Stage Shower Filter. Use our Replacement Filters page, and if you're not sure which model you have, ask us before ordering.

Is installation included?

No installation service is included, but none of the three needs tools or a plumber. See Installation & care for each brand's steps.

Will it affect water pressure?

Crystal Quest rates its shower filter at 2 gpm for 30 to 60 psi, and Sentry rates its filter at 1.5 gpm. A drop in flow usually means the cartridge needs replacing. GoodFor hasn't shared a flow figure with us.

Can I use it in a rented home?

All three screw on between the shower arm and the shower head and come off the same way. Rental arrangements differ, so check your lease or ask your landlord if you're unsure.

What is included?

Each product page lists what's included. Cartridge pack sizes are the number of cartridges, and cartridges are sold without the filter housing. Where a brand hasn't listed every item in the box, we say so.

Can I buy without subscribing?

Yes. Every product is a one-time purchase. We don't offer subscriptions at the moment.

How much is shipping?

GoodFor and Sentry filters and cartridges ship free. Every other item ships at the brand's own rate, shown on its product page and at checkout before you pay; Crystal Quest, for example, charges $7.95 to $9.95. Every item ships from a US warehouse. Read our Shipping policy and Returns policy.