“The Matrix”
– a do-it-yourself hydroponic garden
This design makes use of the
AeroGarden™ pods
(Aeropod) and sponges that
are available online (Ebay) in
bulk (50 each)
This design also uses
pea gravel (or aquarium
gravel) to support the
plant as it grows larger
This design also uses 4 inch
plastic net pots (Amazon)
Note: the basket slats will
keep the pebbles from
clogging the overflow and
drain outlets, so just make
sure the pebbles are larger
than the slat openings…
This design also uses 4 inch PVC
pipe and fittings. You will need
something to cut this to length.
This can be a hacksaw, rotary
saw, or large pipe-cutter. Note
that clear PVC is also available
(but also much, much more
expensive than white)
6”
4” PVC Sched 40
1
3
/
4
4” PVC Sched 40 4” PVC Coupler
3”, 4” Closet Flange
(Oatey #43557)
4” Round Plant Basket
Parts list (mostly complete…)
Note: make this
longer if you need a
larger volume. With
this plan the garden
will be about 500ml
Oatey Heavy Duty Clear PVC Cement
Some Teflon tape
Something to cut PVC pipe with (e.g. hacksaw)
Black vinyl tubing ½”, 5/16”, and ¼” I.D. (also 1/8” ID)
5 gallon bucket
3/8” MNPT x 3/8” hose barb (US Plastics #61136) x2
¼” MNPT x 3/16” hose barb (US Plastics #61153) x1
Small submersible fountain pump (e.g. 75 gph) – best if it is adjustable!
Cyclical timer for power
Table/stand (5 gallon bucket can fit underneath)
Air stone (optional)
7/16” and 37/64” drill bits (intermediate drills for pilot holes; 3/8” chuck drill)
¼” CS NPT TAP, 3/8” CS NPT TAP (and tap handle)
Parts list (cont…)
4” PVC Sched 40
4” PVC Sched 40
4” PVC Coupler
3”, 4” Closet Flange
1. Puts lots of glue here:
(this is a notoriously loose fit)
Inside
2. Glue here:
Inside
2. Glue here:
Inside
Top should be flush with coupler
After assembly
Note on the coupler:
It might seem strange to have a coupler instead of just extending the length of the 4”
PVC pipe. However, the coupler adds width to permit tapping of a threaded hole having
a useful depth. Conveniently, the threaded nylon fittings end up being flush with the
inside wall.
The bottom closet flange serves the same purpose, and importantly also prevents the
apparatus from tipping over.
37/64” Drill (overflow hole)
1
1
/
4
7/16” Drill (drain hole)
37/64” Drill (input hole)
9
/
16
Front
Back
Input and overflow holes: tap
3
/
8
” NPT thread
Drain: tap ¼” NPT thread
Overflow fitting:
3
/
8
” MNPT x
3
/
8
” hose
Input fitting:
3
/
8
” MNPT x
3
/
8
” hose
Drain fitting: ¼” MNPT x
3
/
16
” hose
(wrap Teflon tape around the threads!)
7
/
8
Pilot holes:
1
/
8
,
3
/
16
, ¼,
5
/
16
,
7
/
16
(stop on
drain hole), ½ (fill and overflow),
37
/
64
9
/
16
37
/
64
hole
Drill 37/64” inlet hole into basket
Line up basket hole
With inlet hole
After basket is installed insert short
(e.g. 1 ½”) length of 3/16” tubing
through basket and into the inlet fitting.
Cut 3/16” tubing to length and with an
angle so that inlet water feeds top
center of the unit.
This is how the cup/sponge is
positioned and the pebbles are
filled. The inlet tube through the
top of the cup is beneath pebbles
Side view showing unit on table
above 5 gallon bucket containing
pump. The nutrient inlet (left) and
overflow (top right) and drain
(bottom right) are visible
The 4” mesh cup is inserted. The short
½” tubing is inserted from the inside of
the cup into the inlet. An empty
Aeropod holder is covered with masking
tape and centered in the cup. Gravel is
poured to secure the Aeropod holder.
Then remove the tape.
Eco66 pump
(75 gph adjustable)
5 gallon bucket
(volume of water/nutrients is 2.5 gal;
this can be increased if more than one
garden is connected )
Inlet
Overflow
Exit of overflow and drain tubes must be
above the water level in bucket (i.e. tubing
end is open to air) and should not sag
down below the opening
Drain
Unit raised up on
table or shelf above
5 gallon bucket
Balancing the Water Flow
Pump output may need to be adjusted to:
1. Provide sufficient flow to fill unit up to the overflow level
If necessary increase the flow of the pump (use an adjustable pump)
If the drain is too fast to permit filling of the unit, then cut the drain tubing about 2” long
and insert a smaller diameter drain tubing into this (e.g. use 1/8” tubing) – this will slow
the flow of the outlet
2. The pump flow should not be so great as to overwhelm the overflow (i.e. cause a flood out
the top of the unit)
The only way to deal with this is to get a smaller pump! (or you could tap two drain
lines…)
A small trickle from the overflow is sufficient to indicate filing to the correct level. The
primary flow is out the drain, not the overflow, but the water level to the level of the
overflow is critical to achieve
3. A cycle timer for the pump is needed. This would be set up to be 90 min on/15 min off. This
permits gas exchange to the roots without drying them out
4. Multiple units must be connected in parallel and ideally with some ability to control water
inlet flow to each unit
Inlet
Overflow
Drain
Inlet
Overflow
Drain
If input flow exceeds drain
outflow, nutrient level will
continually to rise. However, the
overflow outlet will prevent
flooding.
Some plants like this much water
Nutrient flow from top
to bottom. Some plants
like this much water
Nutrient Flow
Inlet
Overflow
Drain
1. Nutrient flow into inlet
Inlet
Overflow
Drain
Inlet
Overflow
Drain
3. Flow out overflow
(maintains top level
of nutrient)
2. Flow out drain
(establishes nutrient flow
from top to bottom)
4. Pump cycle (90 min ON/15 min OFF)
Nutrient level goes down to drain level, permits gas exchange of roots.
You can also add an air bubbler to the 5 gal bucket
Nutrient Flow
Expanding the System
The pump outlet can be connected to a “T” fitting
to provide nutrient flow to two systems; however:
The drain tubes should be independent, as well
as the overflow tubes
The reason for this is that T-fittings can introduce
bubbles/back pressure in the system that can
prevent drainage. Also, with separate drain and
overflow tubes, nutrient flow for each unit can be
monitored
Additional units can be connected with more T-
connectors to the pump outlet
Eco66 pump
(75 gph adjustable)
Inlet
Drain
Overflow
Inlet
Drain
Overflow
Inlet
Single unit
Double unit