Dymax Slim Flo Filter Cartridge, 2-Pack, Med/Lg

Replacement Filter Cartridges for the Dymax Slim Flo SF-240 and SF-500

The Dymax Slim Flo Filter Cartridge (Medium/Large) is the scheduled replacement media for the SF-240 and SF-500 filters. Each 2-pack contains two wool carbon cartridges that drop directly into either filter housing with no modification. The wool layer captures suspended waste and particulates while the carbon layer clears discoloration and dissolved organics, restoring both mechanical and chemical filtration capacity in a single swap.

One cartridge size covering two filter models simplifies restocking for hobbyists running multiple tanks. Whether you have an SF-240 on a shrimp tank and an SF-500 on a planted community tank, a single pack covers both. Replacing on a 3 to 4 week schedule keeps flow consistent and prevents the media from becoming a source of nutrients rather than a remover of them.

Key Features:

• Fits both the Dymax Slim Flo SF-240 (5–8 gallon) and SF-500 (10–24 gallon) filter models
• 2 cartridges per pack for back-to-back scheduled maintenance without a restock gap
• Wool carbon construction handles mechanical and chemical filtration in one replaceable unit
• Drop-in fit requires no cutting or modification to the filter housing
• Removes suspended waste, particulates, and water discoloration

Ideal For:

• Hobbyists running both an SF-240 and an SF-500 who want to stock one cartridge size for both units
• SF-500 owners running planted tanks or community tanks up to 24 gallons on a regular maintenance schedule
• Planted tank keepers who want a straightforward, low-cost media refresh with no DIY cutting or fitting

Pro Tips:

• One pack covers both filters if you run an SF-240 and an SF-500. The Medium/Large cartridge is interchangeable between the two models. You can rotate from one to the other without buying separate media for each tank.
• Replace on a schedule, not when flow drops. A partially loaded cartridge in a 10 to 24 gallon tank can accumulate enough nutrients to begin leaching back into the water before flow is visibly affected. Every three to four weeks is a reliable interval, regardless of how clear the water looks.
• Rinse the filter housing when you swap the cartridge. Debris that settles in the plastic housing between cartridge changes will re-enter the tank with fresh media in place. A quick plain-water rinse of the housing at swap time keeps the filter running cleanly.

Online exclusive: this item is ordered in for you and is usually ready within a few business days. Choose in-store pickup, local delivery or shipping at checkout.