Re: Under ground filter or not?

[IDMiamiBob@aol.com]

Erik wrote:

<< One last question, how do you deal with the mechanical filtration with
< this setup?  It sounds like you would skim any surface muck down into the
< undergravel, and you'll just settle all your waste just on top of the
< gravel, right?  >>

Not quite.  The whole point of reverse flow is to get the stuff below the
gravel.  Everything colid settles on the bottom of the tank, below the filter
plate.  As far as I can tell, the fatty and proteinous stuff that skims off
the surface floats back up through the gravel, and is consumed by plant
roots, and bacteria in the gravel bed.  Most people say you shouldn't put
things like rocks or whatnot onto the surface of the substrate because it
will create dead spots. [ But if you don't overstock, the dead spots should
turn anaerobic.  As far as I can tell, the stuff off the surface, which some
people remove in salt-water setups by foam fractionation ( protein skimmers)
, is the same stuff they reintroduce later into their anaerobic filter
chambers as "bacteria food". ] The couple sentences I have placed between
brackets is purely personal conjecture based on what I can glean from
magazines and personal experience.  If I'm right, this should help keep the
nitrate levels down between weekly water changes.  What I know for sure is
that when I changed intake guards from the fan style to the straight to
improvesurface skimming, the surface cleared up in a couple days.
And yes, sure , you can include this stuff in your article.  I'm going to
check out the web page you refered to tomorrow.  I'll let you know how it
looks.