Unicel Replacement Filter Cartridge 25 sf Freeflow Spas CLX | 4CH-23
Unicel
SKU: 4CH-23
Unicel 4CH-23 Replacement Spa Filter Cartridge (Top-Load Style)
The Unicel 4CH-23 is a replacement pleated spa filter cartridge designed for select hot tub and spa filtration systems that use this specific cartridge style and fitment. Replacing a worn or damaged cartridge helps restore circulation, improves water clarity, and reduces strain on spa pumps and heaters.
Key Features
- Replacement spa cartridge filter for compatible filter canisters
- Pleated media captures fine debris for clearer water
- Durable end caps and rigid core built for repeated cleaning cycles
- Helps maintain steady flow when rinsed and cleaned on a routine schedule
Compatibility Notes (Important)
- Many spa cartridges look similar—match by part number (4CH-23) whenever possible.
- Before ordering, compare your existing filter’s:
- Outside diameter and overall length
- Top end style (open, closed, handle, or cone/knob)
- Bottom end style (open, slip, or threaded—if threaded, confirm thread size/type)
- If your current cartridge uses a threaded screw-in base, confirm the thread type matches exactly.
When to Replace
- Pleats are torn, frayed, flattened, or separating from the end caps
- Flow is weak or the spa struggles to circulate even after cleaning
- Water stays cloudy despite balanced chemistry and normal sanitizer levels
- End caps are cracked/warped or the inner core is weakening
What’s Included
- (1) Unicel replacement spa filter cartridge
Related Products
- Spa Cartridge Filter Cleaner
- Cartridge Cleaning Wand
- Spa Water Test Strips
- Spa Fill / Hose Pre-Filters
- Spa Scale Remover
Maintenance Tips
- Rinse the cartridge regularly (often weekly with heavy use) to prevent restriction and keep jets performing well.
- Deep clean every 3–6 weeks with a cartridge cleaner to remove oils; rinse thoroughly before reinstalling.
- If scale is present, degrease first, then treat for scale (never reverse the order), and rinse completely.
- Rotating between two cartridges (one in use, one drying after cleaning) can extend overall filter life and improve filtration consistency.
Questions about returns? View our return policy.
Hours Of Operation:
Monday - Friday: 7:00 am to 5:00 pm Phoenix Time
Saturday: 8:00 am to 2:00 pm
Sunday: Closed
- We do not ship on Saturday or Sunday.
- Orders totaling more than $300 will require signature confirmation upon delivery.
- We process and prepare orders for shipment within 1 business day. Please note that many other pool supply retailers require 3–5 days of handling time before shipping.
- Orders placed after 1:00 pm Phoenix Time may not be eligible for same-day shipment.
- Expedited shipping options are available at checkout.
Return Policy:
- Products that are received damaged will receive a refund in store credit.
- Most products are eligible for return within 30 days of receipt, except where noted below.
- To initiate a return, please complete an RMA form prior to sending your item back.
- Original shipping costs are non-refundable and will be deducted from the return credit.
- Items returned missing accessories or original packaging, or that are not in the same condition as received, may be subject to a restocking fee of up to 100% depending on the condition of the item upon return.
- Some returns will be charged an automatic 15% restocking fee.
- We are unable to issue refunds for items that have been damaged or rendered inoperable due to installer error.
- Please complete the return form to receive your RMA number and return shipping label.
- Chemical products are not eligible for return under any circumstances.
- The Pentair Colorsync 618031 is not eligible for return.
- Pool cleaners are not eligible for return.
- Opened seals and o-rings are not eligible for return.
- Capacitors are not eligible for return.
- Plastic popup tools are not eligible for return.
- Automation components and circuit boards are not eligible for return.
- If a light is returned due to a reported malfunction and is found to be fully operational upon testing, return shipping costs and a restocking fee will be deducted from the refund.
- Orders refused at the time of delivery will be subject to the original shipping costs being deducted from the refund.
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