300 Micron Filter Socks — 7" x 12" Reusable Sump & Pond Filter Bags with Built-In Plastic Rim

🐟️300 Micron — Clear Water Without Choking Your Flow

Traps fish waste, uneaten food, leaf litter, and fine debris. 300 micron is the sweet spot: fine enough to polish water clear, coarse enough that it doesn't clog in hours and kill your circulation. Ideal for koi ponds and large sumps.

🐟️Heat-Sealed Bottom — No Fraying, No Seeping

The bottom seam is heat-welded, not stitched, so there are no holes for debris to escape and no threads to unravel. Aquarium-safe polypropylene holds up to repeated rinsing and reuse without splitting.

🐟️Built-In Plastic Rim — Sits Securely on Standard 7" Holders

The sock has a white plastic rim sewn into the opening. Drop it into a 7" filter sock holder and the rim rests on the opening, keeping the sock in place. No tools, no hardware. The 12" depth gives you generous surface area for steady flow.

🐟️Fit note: Works best when your holder opening matches the rim diameter. If your opening is slightly smaller or larger, the rim may not seat flush. Not sure? Message us your sump model and we'll confirm.

🐟️Washable & Reusable — Rinse, Dry, Reuse

Hose off heavy debris, rinse in a bucket, air dry. No special detergent. Reusable for multiple cycles without losing filtration efficiency. One 2-pack replaces dozens of disposable socks over a season.

🐟️For Koi Ponds, Large Tanks & Water Gardens

Works in koi ponds, freshwater and saltwater large aquariums, water gardens, and decorative fountains — anywhere you have a standard 7" filter sock holder.

Product Description

Tired of cloudy water, side leaks, and filter socks that slip or tear mid-cycle? This heavy-duty 7" filter sock is built for koi ponds, large aquariums, and outdoor water features.

The sock features a white plastic rim built into the opening. Drop it into a standard 7" filter sock holder and the rim rests on the opening, holding the sock in place without tools or hardware. The heat-welded bottom seam eliminates fraying and seepage, and the tear-resistant, aquarium-safe polypropylene is built to survive repeated cleaning.

At 300 micron, it catches the fine debris that clouds your water without clogging so fast that your flow drops. That means clearer water, steadier circulation, and fewer sock changes.

Installation takes seconds. Just drop the sock into a 7" holder — the rim seats on the opening. You can run multiple socks across your filtration stages for more surface area and better clarity.

Fully washable and reusable. Rinse, dry, reuse — no special detergent. All materials are non-toxic and safe for fish, plants, and invertebrates in both freshwater and saltwater.

If your system uses a 7" filter sock holder, this is a practical, reliable upgrade. Not sure it fits? Send us your sump or filter model — we'll confirm before you buy.