Red Sea Felt Filter Sock 100 Micron 4 in x 10.5 in — Fine Water Polishing

The Red Sea 100 micron felt filter sock is the finest grade in the range: it is made for final water polishing in an established tank, when little particulate matter remains and you want the water perfectly clear.

Where the 100 micron fits in the Red Sea range

Red Sea offers three reusable 10.5 in (26 cm) filter socks, all built on the standard 4 in (10 cm) ring of REEFER and MAX-S aquariums — and of any standard 4 in filter sock holder, whatever the brand of your sump. The thick felt traps particles throughout the full depth of its wall. The 100 micron is the polishing grade: Red Sea recommends it for mature aquariums whose water is already low in particulate matter. For everyday use, the 225 micron felt sock goes longer between cleanings, and for a brand-new setup, the 225 micron thin-mesh sock is the easiest to clean.

Official specifications

• Rating: 100 micron — felt
• Length: 10.5 in (26 cm), 4 in (10 cm) ring
• Fits: REEFER, MAX-S and any standard 4 in sock holder
• Reusable and washable

Our advice

Always run the finest mesh you can put up with. The finer it is, the more it filters — but the faster it clogs. Personally, I prefer the 100 micron and I clean it often. If frequent maintenance is not your thing, the 225 will let you breathe longer between cleanings. And if you are done with filter socks altogether, a ReefMat does the job more effectively than any sock. — Stéphane, Aquarium ReefSolution

Why buy at ReefSolution

Authorized Red Sea dealer in Laval, QC, with fast shipping across Canada. Tired of washing filter socks? The NanoMat replaces 4 in socks with an automatic fleece roller, and the Filter Media Cup turns the same holder into a media cup for carbon, resins or floss.

Frequently asked questions

Should I choose a 100 or 225 micron filter sock?

According to Red Sea, the 100 micron provides fine polishing of water that is already clean, in a mature tank. The 225 micron felt is the everyday choice and needs cleaning less often than the 100. The 225 micron thin-mesh is ideal for new setups or after heavy maintenance, when the water carries a lot of particulate matter.

Does it fit my REEFER aquarium?

Yes: these 10.5 in (26 cm) socks are designed for Red Sea REEFER and MAX-S systems, and fit any standard 4 in (10 cm) filter sock holder, regardless of your sump's brand.