Reef Tank Before Crash 12-2-2012







Many of us in the reef hobby use filter socks to remove larger particles out of our aquarium. Over the years, we have heard much confusion around how to effectively use these filter socks. Sounds simple right? Put the sock around the drain lines from your overflow boxes you have on your tank and change it when it gets dirty. What’s the big deal?  Well,  it turns out by following a few important steps, you can not only use filter socks more effectively in your reef tank, but also how to maintain them and extend their life so that you don’t need to constantly replace them.

What Is A Filter Sock?

Filter socks have been around for ages and have been used in both the freshwater and saltwater aquarium worlds to aid in mechanical filtration.  They are most commonly made of polyester or a fine mesh that is sewn together and has either a draw string or plastic ring around the top.  They come in a variety of sizes which is typically relevant to how much or how clean the water you are trying to pass through them is.  Another variation is how big the holes in the mesh or felt are.  A range of 200-800 microns is most often what we find on the market.

Filter Sock used on main refugium

Benefits Of Using Filter Socks

At our ReefNation facilities, we pass about 1200 gallons an hour from multiple tanks into a sump where there are 2 14X7 inch polyester socks for the water to pass through.  This allows us to remove particles that include excess food, detritus, sand from our sand burrowing wrasses and even snails and crabs that take an unwanted journey through the plumbing.   These socks may also provide for a small barrier to pests that may be trying to travel from one tank to the other.
From a mechanical perspective, keeping large particles isolated can also help increase the life of our pumps.  If you have ever arrived home to a snail being lodged in your main pump in a slow game of escargot, you know what I mean.  Regular use of these socks will aid in keeping your aquarium water clear and free from ammonia and nitrate as the organic waste is filtered out.


Maintaining Your Reef Aquarium Filters

Placing a filter sock at the end of the plumbing from your overflow boxes is the easy part. The tough part is learning how often you  “should” clean and replace them?  I can’t tell you how many times I’ve heard people buy them, use them for a month, then throw them out because they are not sure how to clean them.  Turns out, there is a much more sustainable way to use them!

At ReefNation, we try to stick to a regular maintenance schedule with our filter socks by changing them at least every 2 weeks, if not every week.  Why so frequently?  Well, as they begin to clog up with detritus, they start to lose their effectiveness which will cause nitrate, ammonia, and phosphate levels to rise.  Like most everything else in the reef aquarium world, having any water parameter bounce is not healthy for the tank or anything in it.
Some of the tricks we’ve found to avoid our protein skimmers from “acting up” or micro-bubbles is to actually soak the new or clean filter socks in our sumps overnight before changing them. This helps to ensure the air bubbles are properly released. Then, when we are ready to change the filter sock, simply remove the existing one and allow any trapped water to drain slowly before removing it from the sump. Next, place the new filter sock around the plumbing from the overflow boxes and you’re done!


Chaeto growing in our main refugium


Cleaning and Extending The Life of Your Filter Sock

If you are interested in extending the life of your filter socks, we have a few have tried a few ideas over the years that seem to work well.  Some folks will look at the filter sock, turn it inside out and just rinse it.  Unfortunately, this does not clean out the particles that are trapped within the filter sock and simply gives you a false sense of “clean”.   Here is the cleaning process we use on our tanks at ReefNation:

  1. Take a dirty filter sock and turn it inside out
  2. Quickly rinse the filter sock and try to remove any large particles that were caught in the sock (shells, sand, etc)
  3. Machine wash the filter sock (inside out) on a heavy duty cycle with bleach only; never use standard laundry detergent or other soap products like Oxyclean, etc.
  4. After the heavy duty cycle with bleach, machine wash the filter socks (inside out) once more on a heavy duty cycle with no chemicals or soap products
  5. After 2 machine wash cycles, remove the socks and allow them to dry for 48 hours before reuse
  6. If by chance there is ANY smell of bleach still on them, please use one more plain hot water cycle to remove this.

Filter socks are a great way of helping us filter our aquarium water, but without the proper care and regular maintenance, they can have an adverse effect on your aquarium.  With a few simple steps you can extend the life of these invaluable reef keeping tools and save a few bucks along the way.  Happy Reefkeeping!

Do you have a cleaning routine you would like to share?  We would love to hear about it!