Lava rock cleaning?

As other people have already pointed out, lava rock is not a good bio-filter
material. It's incredibly heavy, eventually gets clogged with muck, not easy
to clean (because it is heavy). The key to a good biofilter is to provide
lots of surface area, preferably out of material that is light, and easy to
periodically clean.

I made mine by placing scotch pads inside of 2 milk crates that I stacked
inside of a 55 gal drum. Along with some nylon shade netting material.
Others have used carpet buffering pads. Nice thing about my setup, is I just
open a drain on the bottom of the drum, then scoop out the milk crates, and
just hose them off.

Just remember, lighter is better when it comes to having to clean.

Sameer

"Tom Wikoff" wrote in message
...
With winter in west-central Ohio on the wane, I am nearly ready to
begin
getting the pond back up and running. This will be the second full year
for the pond. It is approximately 1800 gal with a 200 gal. bio-filter.
That bio-filter has approx. 50 bags of lava rock. Last summer a young
man
at the local nursery/water garden outlet advised me to take out and
replace
the lava rock because of my complaint about string algae. I had never
heard of the need to replace this rock and find the thought of the cost of
replacing it just a bit hard to swallow. Was that sound advice? Can't
the
rock be "cleaned" instead. NOTE: I do keep small bales of barley straw
in
the both the filter and at the waterfall and treat the water with products
recommended by the people who sold me the liner, pump and fish (5 to
date).
The ratio of time I spend maintaining versus enjoying my pond does not set
well with me. Any advice would be greatly appreciated.