A
quaponic systems rely on the nitrification cycle
to supply nitrogen to plants, but if too much is
available, then denitrification can be used to lower
those nitrogen levels.
The systems range from the simple to the elaborate.
At the simplest, water can be scooped out of a small
aquarium and used to water a small houseplant.
Some of the most complicated are large commercial
aquaponic systems that harvest both edible fish and
edible vegetables. In my backyard, I’ve had a simple
aquaponic system running for more than a decade
with minimal fuss. The pump has been replaced
twice, and the fish are (or are the descendants of) the
original fish.
A Simple Backyard Aquaponic System
Water from a small fish pond is pumped to a series of
half wine barrels that start at the top of a small rise and
end at ground level. The elevation of each barrel is key
since they gravity feed one into the other. Each half barrel
contains lava rock and a pipe near the rim leading down to
the bottom of the next half barrel, which is set lower than
the first. The lava rock provides mechanical filtering as
anchorage for the plants and a hospitable environment for
beneficial microbial growth.
A third and fourth half barrel are situated lower and lower
yet, and the bottom barrel empties back into the pond. With
this arrangement, water travels from the pond via pump to
the bottom of the first
half barrel, through
the lava rock to the
top, and then through
the pipe to the bottom
of the second barrel.
It then repeats this
process through the
remaining barrels until
returning to the pond.
“The lava rock
provides mechanical
filtering as anchorage
for the plants
and a hospitable
environment for
beneficial
microbial
growth.”
grow cycle
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