"Ka30P" wrote in message
...

bio media can be bought online or at some nurseries that carry pond
products.
they look like - um... let's see - hollow balls with.... spaces, well,
that
doesn't make sense... remember the unfinished space station from Star
Wars?
Like that. Kind of. ;-)

what works about them is that they have lots of surface area for
bacterial to
grow on, are easy to clean as their spaces and hollows are larger than
those in
lava rock which can clog up.

Other stuff that can work are plastic curlers, shredded packing tape,
vinyl
screening - all rough surfaces, with lots of space inbetween, easy to
clean and
light to lift.

This post brought to you by Kathy "Always One Post Ahead of BV" 30a.



BV.