Far Edge Aquatics Nylon Mesh Filter Sock -200Micron- Aquarium Filter/Media Bag - 4 Pack

Ok I agree with the other review they work very well. don't expect them to filter as well as a cotton/felt sock. They are easy to clean and can be used time and time again. I have three in my sump for my 300 gallon reef tank and change them every week. When I use the felt socks they work well but create a lot of turbulence on the down flow. This sometimes upsets my skimmer settings. In addition the felt socks can only be washed (I wash in machine) a few times before they fall apart.The Mesh filter socks, I just rinse them very well, and rotate them each week. I have 12 of them and have used them all year long and my tank is perfect.

These are better than any other socks I have found. Rinse them off and there good to go again. Just wish they were a 2 inches longer.You have to clean them often which is good as that means they are working.UpdateThese just disintegrated after a couple years. I have some 100micron ones that are great.

Love these in my reef tank sump. Depending on feeding and water I can use them alone or add a pinky pad on top with use of light defuser. Or pull them out all together. Gives you more options on mechanical filtration and way easier to clean than the felt

They do not fit 4" pre-filter holders, but they are easier to clean and manage. I just wished they fit the 4" holders.

This filter socks are a little stiff, but seem to do the job. I have been using them for about a month so far so good.

These do NOT FIT in Red Sea Reefer systems. I'm sure they work great, but I'll never know.....they do not fit in the holder for Red Sea.

Good but not fit for Red Sea reefer need to cut the edges to make it fit in