Red Sea 225 Micron Felt Filter Sock

Keep your Red Sea Reefer or MAX aquarium crystal clear with the Red Sea 225 Micron Felt Filter Sock. This mechanical filtration sock traps detritus, uneaten food, and free-floating particles before they break down and affect water quality. Washable and reusable, it's an essential part of any sump-based filtration setup.

Looking for more filtration products? Browse our Filter Media & Cartridges.

• 225 micron felt media traps fine particulate matter for polished, clear water
• Designed specifically for Red Sea Reefer and MAX series sumps
• 4" x 10" size with plastic ring for a secure, snug fit
• Washable and reusable — rinse and reuse multiple times before replacing
• Suitable for both freshwater and saltwater aquariums

How often should I replace or wash this filter sock?
Rinse the sock in warm water every 3–5 days or when flow slows noticeably. Most hobbyists get several months of use before the felt wears out and needs replacing.

Will this fit non-Red Sea sumps?
The 4" x 10" size with plastic ring is designed for Red Sea Reefer and MAX sumps. It may fit other sumps with a 4-inch filter sock holder, but check your sump dimensions first.

What's the difference between 100 micron and 225 micron filter socks?
A 225 micron sock catches larger particles and clogs less frequently, making it ideal for everyday mechanical filtration. A 100 micron sock catches finer particles for ultra-polished water but needs to be cleaned more often.