Our customer asked:
I found my water filter making a horrendous noise. I have had to turn it off and assume it is completely broken. I have no idea what I should replace it with. My tank is 20 litres and I have two fancy goldfish in it. The old filter is one that is inside the tank held on by a suction. Can you recommend one for me please? Thank-you.
I would recommend A Fluval mini filter for your tank. Since your tank is only 20 litres I would suggestt an Interpet Internal Power Filter, quick find code 119576.
This should fit in your tank easily and comes complete with all you need.