I have a few Hamburg Mattenfilter sponges available for sale..
30PPI and 13" x 13" x 2"
Perfect for 10, 15, 20L and 33L gallon tanks.
Can also be used for other tank sizes, but needs some extra work.
Pickup @ Chilliwack.
PM me if interested.
one thing that comes up often is cleaning the filter material.
! do not wash the filter materials in tap water it will kill off the benifical bacteria we want in out filters.
I remove some water from the tank for a water change.
using that water in a bucket I clean out the filter...