The Salty Side: Saltwater Aquariums for Beginners

How to Clean Filter Socks for a saltwater aquarium

Filter socks, whether you use them regularly or not, are often seen as a pain to clean. If you procrastinate and leave them too long they not only overflow, they also begin to harbour nitrates. Cleaning them too often just seems like a chore to some. To make things work for us, lets look at the easier methods of cleaning filter socks for a salt water tank.

Quick Links:

Cleaning filter socks with or without bleach

Filter Sock Bucket

Bleach is your number one friend (in my estimation) when it comes to cleaning filter socks. I’ll tell you how I wash mine and have done for years.

Its best to have a circulation of socks going. If you use two filter socks at a time, invest in another 6 or 8. This means that when your socks become clogged, you can throw them in a dedicated bucket. When the bucket is full or to ensure you have cleaned them for the next round, put all dirty socks in the washing machine at the same time.

I use polypropylene filter socks for ease of use and ease of cleaning.

How to clean filter socks with bleach:

  • Place all filter socks into the washing machine.
  • I add two capfuls of thick bleach to the fabric softener compartment
  • Wash the socks at 40°C or less on the shortest wash is best
  • Once washed, allow the socks to fully air dry.

It is very important that the socks are allowed to air dry. This will ensure that any bleach residue has fully evaporated and the socks are safe to continue using.

Cleaning filter socks without bleach:

As you would do with bleaching, just wash them in the washing machine without the use of bleach. The downside to washing without bleach is they tend to retain some of the dirt they went into the wash with. When leaving out to dry they can begin to smell, and over time they will become less and less effective.

Is it always necessary to clean filter socks?

The short answer is yes, if you want to keep control of your nitrates. It is however not always required to wash them in a washing machine.

When doing water changes, or when you are disturbing the sand, or at any time you know the water column will become dirty, a filter sock is a fantastic tool for catching all that waterborne dirt. Normally, as soon as I have finished the maintenance and the water has become clear again, I remove the filter sock and replace it with a clean one. Then wash the maintenance one through with fresh water and allow it to fully dry. If it is particularly dirty, then I do add it to the sock bucket.

Are there alternatives to using filter socks?

Thankfully, yes. Filter socks are not the only method to remove unwanted particles from the water column.

Red sea reefer filter cups

Although I use filter socks in my frag tank, due to their ease of use in that situation, the same cannot be said for my main display which uses 4 filter media cups. I had the choice of using filter socks in these holders, but replacing 4 filter socks every two days made them unfeasible. I decided filter media cups would be the better choice.

In my case, I have filled my media cups with Siporax, and placed a layer of filter wool on top of each which I replace every two days with new filter wool.

Not all filter socks are created equal

Its worth adding that not all filter socks for saltwater aquariums are created equally. As well as run of the mill polypropylene mesh 200 micron socks, you also get felt socks.
Felt socks are manufactured to catch smaller particles in the water column and are affective at doing so. The lower the micron, the more effective the sock will be. This does come with drawbacks though. Felt socks tend to block up very rapidly and often end up at the bottom of the pile.

I have used a 5 micron felt filter sock specifically to filter dinoflagellates from my tank.

As a safe bet, if you have not used filter socks before, aim for the 200 micron mesh range.

So there you have it...

Filter socks…not the most engaging topic, but if this article has helped you in any way it was worth it.

It may be worth considering filter sock/media cup replacement entirely. I have, but unfortunately my sump won’t allow it. Roller mats have really taken off but most that have installed them have had to restructure their sumps to some extent.

Scroll to Top