A shower filter cartridge should be changed every 3 to 6 months. Over a year, that adds up to 2 to 4 cartridges for every customer who keeps using the filter. You sell the housing once, and the cartridges follow on a schedule. A shower filter replacement cartridge program is your plan for those follow-on orders: which cartridge fits which model, how customers buy it, what the box and manual tell them, and how much stock you hold.
The end-user side, such as change intervals and the signs that a cartridge is spent, is covered in our shower filter replacement guide. This article covers the brand side: turning that interval into a product line and a repeat sale.
Why the cartridge is your second product
The housing is a one-time purchase. The cartridge is a recurring need with a known rhythm, set by the 3 to 6 month change interval. Give it its own SKU, packaging, listing and stock plan, the same way you treat the filter itself.
Keep the arithmetic honest. Two to four cartridges a year is what a customer needs if they keep the filter in use. It is not a sales forecast. Some customers change on time, some change late, and some stop. Also remember that a cartridge already ships in the box, so in the first year a customer needs 1 to 3 refills, and the full 2 to 4 only from the second year.
The US retail market already treats refills as a normal part of the category. Large marketplaces list shower filters with a subscribe option, and direct-to-consumer brands build it into the product page. Some direct-to-consumer brands, for example, sell their shower system either as a one-time purchase or as a set with a cartridge subscription that ships two cartridges every 90 days, with the subscription priced below the one-time option.
There is a catch. Some shoppers push back on subscriptions they did not choose or cannot easily pause. Whatever you offer, make skipping, pausing and cancelling simple, and keep a plain one-off refill on sale next to it. If you are still at the stage of choosing products and channels, start with our article on starting a shower filter brand, then come back to refills.
Four ways brands sell replacement cartridges
Most brands use one or two of these routes. Each asks something different of you and your supplier.
| Route | Suits | What to prepare with the factory | Watch out for |
|---|---|---|---|
| Single cartridge | Customers who change late or irregularly; marketplace listings | A retail box for one cartridge, its own barcode, cartridges packed separately from filters | Packaging cost per cartridge is highest |
| Refill pack (2 or 4 cartridges) | Customers who want to buy once for six months or a year | A multipack box and a carton count that suits your warehouse | Higher upfront spend for the customer |
| Shower filter subscription | Your own online store, where you control billing and shipping | Cartridge stock planned months ahead; packaging that survives parcel delivery | Complaints and cancellations if the terms feel forced |
| Reminder-led refills | Any channel | A reminder on the product, a change-date space on the box, a refill link in the manual | A reminder only helps if the right refill is easy to find |
| Pack | Changing every 3 months | Changing every 6 months | Best for |
|---|---|---|---|
| Single cartridge | 3 months | 6 months | Late or irregular changers, marketplace listings |
| 2-pack | 6 months | 1 year | Customers who buy once for half a year |
| 4-pack | 1 year | 2 years | Yearly buyers, subscriptions |
A two-pack covers six months at a 3-month interval, or a year at 6 months; a four-pack covers a year at 3 months. On every refill box and listing, name the exact housing it fits.
Hotels and other bulk buyers usually sit outside these four routes. They change cartridges across many rooms at once, so their refill plan looks more like a maintenance schedule with planned bulk orders. Our guide to shower filters for hotels covers that case.
Design the cartridge line before the offer
A subscription is only as simple as the cartridge range behind it. Decide which cartridges you will carry before you design the offer, because every extra cartridge is another SKU to stock, pack and list.
Which cartridges fit which housing
Across the models in Jinko’s OEM shower filter range, cartridge compatibility works like this:
- JK-S4, JK-S5 and JK-S6 share one cartridge. If you sell two or three of these housings, one refill SKU covers all of them, and one subscription works for every customer.
- JK-S3 has its own cartridge, not shared with other models.
- C5, a new model, also has its own cartridge.
A range built on the S4, S5 and S6 runs on a single refill. Adding the S3 or C5 adds a second or third refill SKU. That is no reason to leave them out: the S3 is Jinko’s main model, and its clip-in design makes the cartridge easy for customers to change themselves. It does mean separate stock, packaging and listings for each.
What goes inside the cartridge
The shared S4, S5 and S6 cartridge is a composite of carbon fiber, copper-zinc (KDF-type) media, calcium sulfite and vitamin C. If you want to explain that media to your customers, see what KDF media is. The S3 can be configured with PP cotton plus calcium sulfite, a carbon block cartridge, or a carbon fiber cartridge.
Choose the configuration once and keep it fixed. A refill should match the cartridge the customer found in the box, and your packaging and listing should describe the same media. A custom cartridge formula is possible, but it is evaluated separately, so raise it early if you plan one.
A reminder built into the housing
The JK-S5 is a new model with a decorative filter reminder ring on the housing. For a refill program, that puts the cue to change the cartridge on the product the customer sees every day, instead of in an email they may ignore. If reminders are central to your offer, the S5 is the model to build around, and it takes the same cartridge as the S4 and S6.
Put the reminder in the product, the box and the manual
A filter change reminder works best when it shows up in several places and every place says the same thing.
- On the product: the JK-S5 reminder ring.
- On the box: the change interval (every 3 to 6 months), the name of the matching refill, and a blank space where the customer writes the install date.
- In the manual: cartridge change steps, the refill name, and a web address or QR code for your refill page.
- After the sale: an email or text message timed to the interval, if you sell direct.
Logo, packaging and user manual are standard customization services at Jinko, so your box and manual can carry the refill details from the first order. Settle the wording before you approve the packaging artwork. Changing it later means waiting for the next print run.
Keep the interval identical on the box, in the manual, on your product page, in marketplace listings and in reminder emails. If the box says 3 months and the listing says 6, customers will follow whichever they saw last, and your refill demand gets harder to predict. The consistency checklist for brands and distributors lists what to align.
Some retail brands put a month reminder dial on the shower and link to a reminder program and a refill program from the cartridge page. Whatever form you choose, keep the reminder about timing. Do not tie it to filtration claims you cannot support with test reports for your exact cartridge.
Packaging and pricing the cartridge offer
Packaging
Design the refill packaging together with the filter box. Common formats are a single-cartridge box and a two-pack, and a four-pack is worth adding if you print a 3-month interval. Make the refill box look like part of the same family as the filter box. If you also sell sets, our guide to shower filter gift sets covers presentation.
Jinko’s standard package contains the filter body and a cartridge, without a shower head. If you want an extra cartridge packed in the same box as the filter, for example as a starter bundle, ask for that configuration and its price separately.
Pricing structure
This article does not give price figures, because your landed cost, channel fees and positioning decide them. What you can borrow is the structure many brands use:
- Single cartridge: the reference price.
- Refill pack: a lower price per cartridge in exchange for a larger order.
- Subscription: the lowest price per cartridge, or the same price with a benefit such as free shipping. Some direct-to-consumer brands already price the subscription below the one-time option.
Work out each tier from your own cost per cartridge, packaging, shipping and platform fees. Check that the subscription still covers its own shipping, since each delivery is a small parcel.
Run the numbers
The table assumes 1,000 customers who keep using your filter. That figure is a placeholder: the share of your buyers who keep changing cartridges is unknown until you have your own sales data, so replace it with yours.
| Change interval | Cartridges per customer per year | Refills per customer in year one | Year-one refills for 1,000 customers | Cartridges per year for 1,000 customers, from year two |
|---|---|---|---|---|
| 3 months | 4 | 3 | 3,000 | 4,000 |
| 4 months | 3 | 2 | 2,000 | 3,000 |
| 6 months | 2 | 1 | 1,000 | 2,000 |
Year one is lower because the first cartridge ships in the box. Every number in the table comes from the 3 to 6 month interval. None of it is a forecast or a price. Three ways to use it:
- Set a range, not a single figure. Plan cartridge stock between the 6-month and 3-month rows, then adjust once real refill orders come in.
- Order refills with your filters. At a 3-month interval, your first customers need a new cartridge three months after they buy, so the stock should be ready by then.
- Keep one refill SKU where you can. A range built on the S4, S5 and S6 puts all of these numbers into a single cartridge.
Jinko’s shower filters start from 1,000 units, flexible by model and customization. For cartridges ordered on their own, ask us for the minimum quantity and unit price, since both depend on the model and configuration.
To price your refill line, tell us which models you plan to sell, your sales channels, your expected annual volume and whether you need custom branding or a custom cartridge. We will come back with cartridge options, unit prices, minimums and packaging formats. Send the details through our contact page, or read more about private label shower filter manufacturing at Jinko first.