20R-BB-WH - Refillable 20in x 4.5in Large Diameter Cartridge

This 20 x 4.5 inch large-diameter refillable cartridge shell from WrekinWater is built to the Big Blue format used in whole-house and high-flow filtration systems, giving far more media capacity than a standard slimline cartridge. Instead of buying a sealed cartridge every time, you fill this reusable shell with your own choice of loose media and simply refill it once it's spent. It's sized to drop into any standard 20-inch Big Blue housing.

Why you'd choose a refillable cartridge

• You're treating a whole-house or high-flow system and need more media capacity than a slimline cartridge gives you.
• You want to fill a Big Blue housing with your own choice of media instead of a generic pre-packed one.
• Your existing large-diameter shell has cracked, clouded or the threads have worn.
• You're switching to bulk media to cut the ongoing cost of replacing large pre-packed cartridges.

Big Blue systems typically serve an entire house, so the pre-packed cartridges sized for them tend to be the most expensive to replace like-for-like. This reusable shell removes that recurring cost: you buy media in bulk, fill the shell yourself, and get through it once the media is exhausted or fouled. The larger 4.5-inch diameter also means more media in the water path, so you can go longer between refills than with a slimline cartridge of the same length.

WrekinWater is a family run company that has served more than 50,000 customers over 15 years from its base in Bettisfield, Shropshire (UK Company No. 11000488), and is rated Excellent on Trustpilot. We stock Big Blue housings and valve gear from Pentair Fleck, Autotrol, Clack, Kinetico and other major brands, so if you need help matching media to your whole-house setup our team is happy to advise.

How to fill and fit it

1. Isolate the system and relieve pressure before opening the housing.
2. Unscrew the end cap from the cartridge shell.
3. Fill with your chosen media, leaving headspace rather than packing it to the top.
4. Refit the diffuser pad and screw the end cap back on firmly.
5. Rinse the filled cartridge under a tap before inserting it into the housing.
6. Restore water supply and run to drain briefly before using the water.