Fleece rollers are designed to replace filter socks and eliminate the need for manually swapping out those filter socks every few days.  Sounds nice huh?

A fleece roller is simply an automatic mechanical filter that will remove suspended particles and debris from the aquarium water.  They are typically installed right on the end of your drain so the water can pass through the fleece roller as it enters your sump.

Fleece roller installation

How a Fleece Roller Works

As water exits your tank, it flows down into the fleece roller where it is then forced through a sheet of fleece.  As the sheet of fleece clogs up, the water will move through the fleece much slower causing the water level to rise inside the filter roller. This will trigger a sensor to advance the roll, taking up dirty fleece and replacing it with new. The water can then pass through the clean fleece freely and the water level returns to normal height. 

The design is intended for 100% of the water to pass through the fleece but there is typically a bypass or emergency overflow of some kind that will allow water to flow out of the fleece roller should there be some kind of malfunction. 

A filter roll will typically last 30 days and need to be removed and replaced on a monthly basis which is a manual process but it still beats cleaning filter socks every few days. The old dirty roll of fleece is disposable and the cost of a clean filter roll ranges from $15 - $50 depending on the exact model filter roller you have.  

Rollermat on BRS160

Fleece Roller vs Filter Sock

You might be asking yourself if a fleece roller is really worth the expense, after all, filter socks are super affordable. While the expense up front is certainly more than a filter sock, an automatic filter roller not only saves you time and energy in terms of regular maintenance but they are also a much more effective mechanical filter.

By design, 100% of your drain water passes through a clean sheet of fleece meaning you're going to much more effectively remove debris compared to filter socks. In some cases, a fleece roller can be so effective that you can actually downsize or eliminate your protein skimmer altogether! You can also expect to experience a certain level of water clarity that a filter sock cannot achieve which most hobbyists appreciate. 

The reality is that a filter sock is really easy to neglect and at some point or another the trapped debris in a felt sock will eventually start to break down and release nitrate and phosphate into your aquarium water. With a fleece roller, that debris is constantly removed and never left to rot or be processed by bacteria in your tank.