Review: Bubble Magus sump filter sock and holder


Nathan Hill tests a pair of socks and finds them both simple and effective...

I always take pleasure in finding products which are both inexpensive and practical and this month I laid eyes on, and bought, two of these sump filter socks and their acrylic holders from H2O Aquatics in Essex.

As the name suggests, a filter sock is just that — a cloth bag where water falls into the top via a rigid or flexible pipe from the main tank above, and dirt particles are trapped in the fine material. It is a mechanical filter in its simplest form, yet very effective and good for polishing water or for tanks with no other form of mechanical filtration. 

Critics may say that as well as removing dirt they also remove microfauna, although I’m not too worried about that as microfauna (little creatures) can also feed pests like Aiptasia, which I actively discourage. 

They will need frequent cleaning too, but cleaning them will keep them at their most effective, and the Bubble Magus ones are longer than ordinary types, so should take less time to block. 

Buying two is advised so that you always have a clean one to hand, and the clip-on acrylic sock holders do a useful job and keep your sump in order too. 


Simple, effective and no moving parts to fail. If you have a marine tank with sump, give them a try. You can't go wrong!


4" filter sock £5.98, 7" £6.98 . Filter sock holders 4" £9.99, 7" £14.98.

Why not take out a subscription to Practical Fishkeeping magazine? See 

our latest subscription offer