My veggie filter is the top of my 150 gallon stock tank (3,000 gallon pond). It
is an upflow filter and the top 'layer' is water hyacinths. They get really
green and really tall!

here's the hint from the green water tips
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~ Construct a veggie filter - an area, 10% to 20%, of the size of your pond
surface area. A couple of inches deeper than the plant baskets (the rigid black
mesh baskets made specifically for water plants) you are going to use to plant
in. Plant the baskets with marginal plants with fine gravel. Pump the pond
water through at a turnover rate per hour 1/2 to 1/4 of the pond volume. Veggie
filter uses up many of the nutrients and provides a good place for bacteria to
grow. Build it with a bottom drain (or two) for ease of cleaning - very
important or you'll end up with backups and leaking over the edge. Go here to
read a great description about how to build one
http://hometown.aol.com/k30a/myhomepage/garden.html
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And BV has lots of recent experience with building a veggie filter.


k30a
and the watergardening labradors
http://www.geocities.com/watergarden...dors/home.html