Before buying replacement cartridges you must know your housing size. A cartridge that does not fit may leak or let water bypass the filter.
Common sizes
- 10-inch standard: the most common size in home under-sink and countertop systems.
- 20-inch standard: longer cartridges for higher flow and longer life, common in villas and light commercial use.
- Big Blue (10 or 20 inch): wider housings with higher flow, used for whole-house and commercial setups.
How to find your size
- Read the label or manual of your system.
- Measure the length and the diameter of the old cartridge.
- Take a photo of the housing and cartridge and send it to us on WhatsApp.
Other things to match
- Cartridge type: sediment, carbon block, pleated or resin.
- Micron rating, which tells you how fine the filter is.
- Connection size and O-ring.
Where to buy
See cartridges and housings, filter cartridges and replacement filters. Learn when to change them in how often to replace cartridges and why the right cartridge matters.
Measure before you order a housing or cartridge
Housing sizes follow a few standard formats, but they are easy to confuse. The slim format has a diameter of about 2.5 inches, and the Big Blue format has a diameter of about 4.5 inches. Both come in 10-inch and 20-inch lengths. A cartridge must match the housing in both diameter and length, otherwise water can bypass it and the filter does nothing.
Whole-house filters commonly use the larger format because it gives more flow and a longer service life between changes. Under-sink and compact systems use the slim format. If you are replacing a cartridge, the simplest approach is to measure the old one or note the markings on the housing or its label, and send us a photo.
What to check
- Diameter and length of the cartridge or housing.
- Port thread size, which affects fittings and flow.
- Maximum pressure rating of the housing.
- Transparent or opaque housing: opaque housings help prevent algae growth in sunny places.
- Spare O-ring and a housing wrench for tight fits.
- Cartridge type for the stage. See cartridge types explained.
Housing questions
Can I put a 10-inch cartridge in a 20-inch housing?
Not directly. The cartridge must match the housing length, otherwise it will not seal correctly.
Why is my housing hard to open?
A dry or twisted O-ring, or over-tightening, can make it stick. Use the housing wrench and lubricate the O-ring with a suitable lubricant at each change.
Can I upgrade to a bigger housing?
Often yes, if there is space and the fittings can be adapted. A technician can advise on the best option.
Send us a photo of your housing for help matching the correct part. See why the right replacement matters.
Related reading and products
Related guides
- Under-Sink vs Whole-House Water Filter: Which One Do You Need?
- How to Choose the Best Water Filter for Your Home in Oman
- Why the Right Replacement Filter Cartridge Matters
Need help from Clean Eco Trade?
Our team in Seeb, Muscat supports homes, cafes, restaurants, farms and businesses across Oman. Contact us for a quote or message us on WhatsApp +968 9828 1478. You can also browse our full product range or see all services.
