Reef Filter Sock Holders
Cups that hold filter floss or media in a reef tank back chamber.
The flared rim rests on the chamber wall and the slotted body lets water pass. Each cup is designed to fit the tank we name. Check the fit before you rely on one.
Filter sock holder questions, straight answers.
How does the holder sit in my chamber?
The flared rim rests on the chamber wall, and the slotted body hangs down and lets water pass through. It sits in place on its own, without clips.
How do I know if the holder fits my tank's chamber?
Each cup is made for the chamber of the tank named on its product page. Find your tank model there and that is your cup.
What do I put inside the holder?
Fill it with filter floss or loose media, the same material you would put in a cloth sock.
Does the holder come out easily to clean or swap media?
Yes. The flared rim lets you lift it straight out of the chamber by hand.
Can I use more than one holder in the same chamber?
Yes, if your chamber has room for more than one. Each product page lists the cup's outside size, so you can see how many sit side by side.
Filter Sock Holder Sizing: Cups, Socks, and Sump Chambers Explained
A filter sock holder is a cup that holds floss or media in your sump, instead of a cloth sock. See how it works and what fits today.
Read the guideSwap your cloth filter sock for a printed cup.
Find your tank model and add the cup made for it. Printed to order in the USA.
Need a size we do not stock? Use the custom builder.