Zip Bag Small 12.5" x 5.5" — 25 Mesh Filter Bag with Zipper | Seachem

The Seachem Small Zip Bag (12.5" x 5.5" / 32 x 14 cm) is a fine mesh (25 mesh) filter bag with a corrosion-resistant zipper, designed to hold small to medium-sized filter media. It easily accommodates 1 liter of media, and its fine mesh makes it compatible with granular media such as PhosGuard, MatrixCarbon, PhosBond, and PhosNet. Made of PVC with durable stitched seams, it closes securely without strings or ties.

Main advantages

• Dimensions 32 x 14 cm (12.5" x 5.5") — easily holds 1 liter of filter media
• Fine mesh 25 Mesh — retains small and medium-sized granular media
• Corrosion-resistant zipper — no strings or ties, quick opening and closing
• PVC material with durable stitched seams
• Resistant to bleach, caustics and acids

Use in reef and marine aquariums

The Small Zip Bag is ideal for granular chemical filter media used in cartridge filters, media chambers, and sumps. Its 25 mesh is fine enough to retain PhosGuard, MatrixCarbon, PhosBond, PhosNet, and other granular media without leakage, while still allowing adequate water flow through the media. For fine resins like Purigen or CupriSorb, use the Seachem The Bag, which offers a superfine 180-micron mesh with welded seams.

Technical specifications

• Dimensions: 32 x 14 cm (12.5" x 5.5")
• Mesh size: 25 Mesh (fine)
• Closure: corrosion-resistant zipper
• Material: PVC
• Seams: sewn
• Capacity: 1 liter of media
• Resistant to: bleach, caustics, acids

Media compatibility

• Seachem PhosNet (GFO)
• Seachem PhosBond (GFO + aluminum oxide hybrid)
• Seachem PhosGuard (aluminum oxide)
• Seachem MatrixCarbon (spherical activated carbon)
• Seachem SeaGel
• Seachem Renew
• Seachem Zeolite
• Aquavitro Phosfiltrum

Do not use with thin resins (Purigen, CupriSorb, HyperSorb) — use Seachem The Bag for these media.

Comparison of Seachem filter bags

• The Bag (5" x 9.5"): 180-micron superfine mesh, welded seams — ideal for thin resins (Purigen, CupriSorb) and all media
• Small Zip Bag (12.5" x 5.5"): 25 Mesh, stitched seams — ideal for PhosNet, PhosBond, MatrixCarbon, and fine granular media
• Zip Bag Medium (12.5" x 5.5"): 16 Mesh, stitched seams — ideal for PhosGuard, MatrixCarbon, denitrate, Matrix
• Zip Bag Large (19" x 17"): 8 Mesh, stitched seams — ideal for Matrix and Pond Matrix

Instructions for use

Place the desired filter media in the bag and close it with the corrosion-resistant zipper. Position the bag in the cartridge filter, media chamber, or sump to maximize water flow through the media. Do not overfill—the media should rest loosely enough to allow water to circulate.

Why choose the Zip Bag from ReefSolution?

The Small Zip Bag is the ideal accessory for using Seachem PhosGuard, Seachem MatrixCarbon, or Seachem PhosBond in your filter. Its corrosion-resistant zipper makes regular media replacement easy. For thinner resins like Seachem Purigen, use the Seachem The Bag with its welded seams and 180-micron mesh.

Frequently Asked Questions

Can the Small Zip Bag contain Purigen?

No. The 25 Mesh of the Small Zip Bag is not fine enough to hold resins like Purigen or CupriSorb. Use the Seachem The Bag with its superfine 180-micron mesh for these media.

What is the difference between the Small Zip Bag and the Medium Zip Bag?

Both have the same dimensions (12.5" x 5.5") but a different mesh size. The Small has a 25 Mesh (finer) for fine granular media such as PhosNet and PhosBond. The Medium has a 16 Mesh (more open) for intermediate media such as denitrate and Matrix.

Is the Small Zip Bag resistant to bleach?

The zipper is corrosion-resistant, and the PVC material is resistant to caustics and acids. However, for frequent bleach cleaning (such as with Purigen), the Seachem The Bag, with its welded seams, offers superior durability.