Compatibility can usually be confirmed by identifying the filter style and connection type inside your system.

Our replacement filters are designed for systems that use standard inline filters with 1/4" push-fit connections.

To check your system:

• Open the filter compartment.

• Look for filters connected to each other by small tubing at the top and bottom of every filter.

• Confirm the tubing inserts directly into filter ports or fittings on both ends of each filter.

If your filters match this configuration, your system uses standard inline filters and will be compatible with our replacements.

If your system uses twist-on cartridges (not compatible with our filters), your filters will look noticeably different. See our "twist-on filters" FAQ question below for some examples.

Note for Wellsys® users: Wellsys® has used both filter styles. Some systems use standard inline filters (compatible), while others use proprietary twist-on cartridges (not compatible). Model name, number, or age alone is not a reliable indicator of filter type.

If you’re still unsure, please contact us. For faster confirmation, have clear photos of your current filters available — we may request them to verify compatibility.

Example images of standard inline (compatible) filters below:

UF and RO membranes are not interchangeable within the system’s original configuration. When selecting your replacement filter set, you should select the same membrane that you already have.

To identify your membrane:

• Standard inline UF membranes have two ports (one inlet and one outlet).

• Standard inline RO membranes have three ports — one inlet on one end and two ports on the opposite end (a purified water outlet and reject water outlet).

If you have a membrane filter in your system that has three ports, your system is configured as Reverse Osmosis.

Choose based on what is currently installed in your system.

• If your cooler has four cartridges installed, choose the 4-filter set.
• If your cooler has five cartridges installed, choose the 5-filter set.

If you’re unsure, open the filter compartment and count the cartridges. Feel free to contact us with photos of the inside of your unit and we'll be happy to confirm.

• No-tool fittings are direct replacements for standard 1/4" push-fit elbow fittings. They perform the same function as standard 1/4" push-fit elbows but feature a patented pull-tab design that allows for quick, tool-free removal during future filter changes.

• If your system already uses standard 1/4" push-fit fittings, you can confidently reuse the ones you have. Many customers upgrade to no-tool fittings simply for convenience during future filter changes.

• If your current fittings are difficult to disconnect or your system is installed in a tight space, upgrading to no-tool fittings can make future maintenance significantly easier.

• They may be required if your system uses a different connection style or if you are transitioning from a factory configuration that does not use standard 1/4" push-fit fittings. (example: if your current filters have female ports instead of male ports, the fittings will make it possible to convert from one filter style to the other).

If you’re unsure whether you need them, contact us and we’ll be happy to confirm before you order.

Images below show filters without fittings and with fittings:

We do not stock compatible replacements for twist-on systems.

How to identify twist-on filters:

• Twist-on filters hang from a manifold and typically have no filter ports on the bottom.

If you’re still unsure, please contact us. For faster confirmation, have clear photos of your current filters available - we may request them to verify compatibility.

Example images of (incompatible) twist-on filters are shown below:

No. Most customers complete their annual filter replacement themselves in 20-30 minutes.

If your system uses standard inline filters, installation is straightforward and does not require specialized tools or professional service. The process typically involves turning off the water, disconnecting the existing filters, reconnecting the new ones, and flushing them.

We provide clear written instructions and video Guides to support the process.

If you ever need assistance, we’re happy to review photos or answer questions before or during.

For most home and office use, we recommend replacing your full filter set once every 12 months to maintain optimal performance, water quality, and flow rate.

If your water supply is high in chlorine or sediment, the pre-filters (#1 sediment filter and #2 pre carbon filter) may require replacement every 6 months.

If you notice reduced flow or changes in taste, earlier replacement may be necessary.

For convenience, we've included an optional Subscribe & Save auto-ship selection for our filter sets so you never have to worry about remembering to replace them.

Orders are typically processed and shipped within 24 hours. Orders are shipped Monday-Friday.

We try our best to get orders shipped out the same business day the order is placed (East Coast Time).

Orders are shipped from via UPS or USPS.

• We offer free shipping on orders over $55 with the option to upgrade to faster shipping for $8.95.

• Orders under $55 ship for a flat $12.99 rate with the option to upgrade to faster shipping for $18.99.

• Orders to Hawaii and Puerto Rico are not eligible for free shipping and ship for a flat $19.99 rate. Please note: shipping time to Hawaii and Puerto Rico may take longer than mainland shipping.

You will receive an email with tracking information once your order has been packed and a shipping label has been created.

We do not ship internationally.

We ship within the United States only, including Hawaii and Puerto Rico.

We offer subscription options for select products to simplify routine filter replacement and provide automatic savings (10% off).

• Pre-Filter sets and Individual Filters are available on 6-month or 12-month subscription schedules.

• Complete 4-filter sets and 5-filter sets are available on a 12-month subscription schedule.

• When you purchase the RainTree™ Undersink System using the subscription option:

• Your FIRST SHIPMENT will include the Raintree™ Undersink System with pre-installed filters (10% off).

• Your FUTURE SHIPMENTS will include an annual 4-Filter UF Replacement Set (10% off).

• The replacement filters you receive will match the configuration selected with your original undersink system purchase (Post Carbon or Alkaline Mineral version). If at any time you decide you would like to receive the other filter set version, you can change this yourself in your account or you can contact us and we will be happy to do it for you.

You will receive a welcome email when you first subscribe and you will receive email notifications prior to every shipment to remind you about your upcoming delivery and payment. This will allow plenty of time to edit your filter selection, skip shipments, change shipment dates, or cancel your subscription.

Yes. You can modify, skip, or cancel your subscription at any time through your account.

There are no contracts, hidden fees, or long-term commitments beyond the current shipment.

Need a different delivery schedule? We’re happy to customize your subscription beyond the standard 6- or 12-month options. Just reach out and we’ll be happy to adjust it for you.

If you need assistance, please don't hesitate to contact us anytime.