"robv60" wrote in message
oups.com...
My pond has about a 15-20' long sloping stream/waterfall that empties
into the main body of water. I have been looking at biofilters, plans
and ideas people have posted on this forum and doing a lot of reading.
My question is, instead of sinking and pumping water through a huge
bucket in my pond, filled with whatever media, Couldnt I simply line
the bottom of the stream bead with more rocks and maybe even mix in a
fair amount of lava rock and/or other media for filtration? The water
flows pretty nicely through the stream bed, wouldnt this effectively
filter my water to some degree? Wouldnt the flowing water from the
"falls" running around the rocks essentially be the same thing as
pumping water through a filter box filled with lava rocks? Seems like I
could spread the filter media out over a larger area and provide a more
natural look to the pond while at the same time filtering. Functional
and unnoticable filtration that simply looks like part of the pond
rather than an unsightly 55+ gallon bucket sunk in my pond. The pond is
2835 gals. I will be using(whenever it gets here) a 3500 GPH pump that
pumps 2785 GPH @ 5' to power the waterfall and circulate the water.


The problem with lava rocks is that they easily get clogged with muck and
lose their effectiveness. They also don't have a very good surface to weight
or surface to volume ratios. They're difficult to clean and just heavy. But
some people like them, obviously I don't. Instead of tossing a bunch of
lava rocks into the stream bed. Try this idea:

It was posted here by someone a few weeks back.

http://www.mvwgs.org/filter.htm

Instead of using lava rocks, I suggest you first try buying a bulk pack of
green scotch pads from resturant supply store first. As a bonus, you can put
a pot or two top of the millk crate and use it as a for a plant which will
hide the milk crate to boot.

-S