Red Sea REEFER Filter Media Cup — 4"

Red Sea REEFER Filter Media Cup — 4"

Overview

Swap out filter socks for flexible, user-friendly filtration. The 4" Red Sea REEFER Filter Media Cup drops into standard 4-inch sock holders so you can run disposable filter floss, activated carbon, GFO, resin, or biomedia without special reactors. It’s quick to service, easy to customize, and helps you fine-tune mechanical and chemical filtration in minutes.

Key Features

• Direct Sock Replacement – Fits standard 4" holders found in REEFER sumps for plug-and-play use.

• Customizable Filtration – Load with floss for polishing, carbon/GFO for clarity and nutrients, or biomedia as needed.

• Fast Service – Lift, dump, and reload in seconds—no sewing, rings, or mesh socks to wash.

• Rigid, Perforated Body – Even flow through media; resists collapse and channeling.

• Reusable & Cost-Effective – Pair with inexpensive floss sheets or bulk media to reduce consumable costs.

• Easy Visual Check – Open design makes it simple to see when it’s time to change media.

Product Specifications

• Type: Reusable 4" filter media cup (sock replacement)

• Compatibility: Standard 4" filter sock holders (Red Sea REEFER and other 4" brackets)

• Material: Durable, aquarium-safe plastic with perforations

• Use With: Filter floss/pads, activated carbon, GFO/phosphate remover, resins, small biomedia

• Placement: Sump intake / filter sock chamber

• Maintenance: Replace floss every 1–3 days (bioload dependent); refresh chemical media per manufacturer guidance; rinse cup during changeouts

• Tips: Place coarse floss on top to trap large debris; avoid over-packing to maintain steady flow and sump water levels