What size filter do I need for my fish tank?

Ideally your fish tank filter needs to be filtering all the water in the tank a minimum of 4 to 5 times per hour. For example, if your tank is 40 Litres you will need a filter that can filter at least 160-200 litres per hour.

Many filters include the tank size they are suitable for on their packaging. For example the Bioscape Velocity Internal Filter comes in a range of sizes to suit tanks from 40L to 200L and the Serenity Sponge Filter comes in a range of sizes to suit tanks from 8L to 200L.

If you cant recall the size of your tank, grab a measuring tape and perform a quick calculation as follows: Multiply length x width x water level height (all in cms) and divide by 1000 for litres.