A combined DWC tub and SCROG screen for a single plant. What you will need
- Light proof tub with well fitting lid (at least 20ltr capacity)
- 20mm pvc pipe for scrog frame (i used a total of 5x1m lengths)
- 4 x 90deg fittings (to suit pipe)
- 4 x 45deg fittings
- 4 x 'T' fittings
- 4 x end caps
- Welded wire mesh fencing material (pref plastic coated, 50mm square spacing)
- Anti fungal silicone sealant
- pvc glue
- net pot (4" or 6")
- air hose and air stones (and air pump of course)
- time (approx 4hrs if all materials present)
DWC/SCROG is based on a thread i sa
w on overgrow so i don't want to
claim it is my design, just my interpretation of it. i don't remember
the author, so i can't give them their due credits, but thanks anyway
to whoever it was. my grow is a small affair, consisting of 2 plants
under a 600W hps (in flower), with a total SCROG area of 900mm x 900m
this means that manual water changes are not too difficult so i didn't
bother with a re-circulating system.To begin with i sorted out the crate/bucket
Important note -
Since these screens have been made I have done a few small alterations
to the way they look in the photos which will be explained later in the
This was a 25 ltr
crate from bunnings. it is black in the body but unfortunately the lids
they had to fit them were almost totally transparent, so i had to spray
them to try to make them more light proof..
- This is
one of the aspects of the design that i have changed since
construction. i found that the flat white paint on the lid was not as
light proof as it could have been so i covered the lid in black gaffer
tape subsequent to construction.
I then cut a hole in the lid to
accommodate the net pot. same old story, make the hole a little smaller
than the net pot so that the lip at the top of the pot rests on the top
surface of the lid.
Next i made four holes, equally spaced in
from the corners. i use 20mm pvc pressure pipe for the construction of
the SCROG screen (available at bunnings, including all manner of
fittings to suit). the name "20mm pvc pipe" is deceiving, i think that
is an internal diameter of the pipe because the outside diameter is
nearly 25mm so the holes were drilled at 25mm.
The next holes are
drilled into the body of the crate itself and are to allow the air
lines for the air-stones to pass into the DWC. these should be drilled
to almost exactly the same diameter of the airline that you will be
using, this will create a snug hold around the airlines and prevent any
light leaks into the DWC or minor water leaks out of it.
Next job was to
cut the airlines to go from the pump to the air-stones to the required
length and install the air lines through the holes i drilled earlier.
The SCROG screen
These are the fittings that are required for the SCROG
4 x 90 deg fittings
4 x 'T' fittings
4 x 45 deg fittings
4 x end caps
There are only a
few critical dimensions in the construction of the screen, the spacing
between the holes in your lid to allow the vertical legs of the SCROG
to pass through, the height of your screen from the lid of your DWC
bucket and the overall dimension of the finished screen (to suit your
With this in mind i cut the lengths of pvc required
to achieve these dimensions. this should be self explanatory once you
see the pictures. however it is not worth giving dimensions here as it
depends on the size of your DWC, your overall desired screen size etc.
Next i made the wings
of the frame. these project out from either side of the core structure
and can be made as wide as is needed to suit your grow space/light
intensity. the length of the 2 end pipes of the frame (running
vertically in the photo) dictate the overall width of the finished
Subsequently, i built the 2 halves of the core structure. these consist of 2 'T' fittings joined by a length of pvc.
note that in the photo i have already attached the wings of the screen
to one half of the core structure. it is advised to make the core
structure parts independently so that the 2 'T' pieces can be lined up
with eachother prior to attaching the wings.)
This length of pvc
that joins the two 'T' pieces is determined by the distance between the
holes in your DWC lid and should be cut so that the pipes that project
from the vertical part of the 'T' fitting are the same separation as
the holes in the lid.
once you have the 2 core structure assemblies and the 2 wing ends of the SCROG it is time to assemble the frame.
It is important at
this stage to fix the core structure assemblies to the wings so that
the projections from the 'T' pieces stick out at a 45 deg angle from
the overall plane of the screen. then these projecting pieces from the
'T' are cut to a length so that they also line up with the the holes in
the DWC lid.
Once they are cut to length, place a 45 deg angle
fitting to the end of each projection. this means that all of the legs
of the screen will sit in a vertical orientation and line up with the
holes in the DWC lid.
However, before attaching the legs to the screen assembly, it is advised to attach the mesh to the frame.
For the mesh i used a
'welded wire mesh' fencing product from bunnings. it comes in rolls
900mm wide so it is the perfect width for my 900mm x 450mm screen. this
mesh comes in plastic coated version which is the one i used and the
hole size of the mesh is 50mm x 50mm
I used the small cut offs that were left on the end of the roll as small twist ties to attach the mesh to the frame.
fixing the mesh to the screens, it is time to attach the legs to the
frame. the legs should be cut to a length so that when they are put
through the holes in the lid and are resting on the floor of the DWC
bucket, the SCROG screen should be about 200mm - 250mm above the lid.
put the legs through the holes in the lid, i recommend that the ends of
the legs are closed off with 'end cap' fittings. this is an additional
feature that i don't have a photo for, but i decided on adding the end
caps after suffering a bout of root rot. with the end caps fitted to
the legs, none of the nutrient solution enters the inside of the frame
and to clean the frame you simply have to clean the external surfaces
of the legs. (when fitting the end caps you must drill a small hole
somewhere discreet on the upper part of the frame so as not to compress
the air within the frame when fitting the final leg end cap.)
the end caps are fitted you should put the lid/SCROG assembly in
position, in the DWC bucket as in the photo above, and ensure that the
lid is fully pushed own home onto the bucket. this means that the lid
is set at the correct height on the legs of the screen and the weight
of the screen is supported on it's legs.
Now you can fix the lid
to the legs by applying a good thick fillet bead of bathroom (anti
fungal) silicone sealant around each leg.
is important to let this first lot of sealant, on the upper surface of
the lid, to dry and adhere overnight. then, the next day you can invert
the whole assembly and apply a second lot of sealant on the underside
of the lid.
Once this has dried it will ensure that the lid is fixed to the screen at the perfect height.
well, that is pretty much it. the net pots can be inserted into the
holes in the lid, put the whole thing together and put it in the grow
written by Jaguarrh