Semi-Automatic Hydroponic Planter/Sprout Grower

I love the idea of growing my own sprouts and plants, but find my schedule too chaotic to commit to regular waterings and maintenance. Some may call it laziness. I wanted to automate a system and realized an otherwise untapped abundance of fresh tap water goes down the toilet each day. I also live in an apartment so any systems involving water MUST be closed and/or have overflow protection. The toilet solves these issues as is. I've been knocking this idea around in my head for awhile, so here goes.

Theory is that since sprouts need to be rinsed at least once a day with nutrient free water, why not utilize the many times a day that a toilet is flushed to remove the labour and memory factors from the equation while all the while looking for uses for 2L pop bottles.

It consists of a fill tube, a grow chamber and a bracket to support the assembly above the tank's water level to allow proper drainage and avoid contamination.

Please keep in mind that this ugly little contraption is a prototype and can easily be enclosed or made more attractive and/or permanent. It can also be expanded upon to provide gravity fed multi-level, multi-chamber systems that even provide nutrients to the point of rediculous. In Theory, that is.

Other plants could also be grown if light conditions allowed and feeding provisions were built in. Grow chambers and fill tubes could be customized to meet various requirements.

Step 1: What You'll Need

Tools - 1 pair of scissors
1 pair of pliers
1 lighter or torch
Drill bits as required (Drill not shown)
Materials - 1 length of flexible tubing, length and diameter as required. (I used clear vinyl, 3/8 ID)
1 2L bottle, cut in half (cut along bottom of label)
1 2L bottle bottom (cut the same, but discard top)(shown in green)
1 2L bottle cap
1 bracket or platform to secure bottle in place (mine was a handy piece of plastic, but I intend to make it more permanent and pretty)(not shown in this photo)

Note: The tubing and bracket will vary from toilet tank to toilet tank as well as personal preferences and resources at hand. I threw mine together quickly just to test it's basic function and look for problems.

Step 2: Inspect Toilet Tank

This is required to determine how to connect the tube and bracket to the tank's existing hardware.

Bracket - It must support an inverted 2L bottle (in this design at least) with no physical contact between
tank water and grow chamber drainage and must allow relatively undelayed drainage back
into tank. I chose to replace the tank lid with another horizontal surface through which I could
drill a hole and mount the bottle. Plastic is easier to drill and replace than porcelain.

Fill Tube - Simply mate the fill tube with the tank's existing fill "spout", whatever it may be, in order to
divert thte water so that we can insert our "grower", in series, into the existing pathway of the
water before it fills the tank.

Step 3: Fill Tube

Depending on your filling requirements, you may wish to leave the tube as is or you may wish to modify it. I chose to modify it so that it would act as a shower head to ensure maximum coverage.

To do this, I simply drilled a bunch of holes through the tube and crimped the end. Drill enough holes to eliminate pressure build up and to cover the desired area inside the bottle.

To crimp the end, simply heat the end 1/2 inch or so, without burning it, and pinch shut with a pair of pliers and hold. If it doesn't seal shut, heat it a little more and try again. Heat slowly to prevent discoloration, but enough to liquify the vinyl. If you use another material, terminate accordingly.

Step 4: Grow Chamber Assy

The grow chamber consists of a strainer inside another container that allows access to interior and provides unhindered drainage. Drainage rate can be controlled by drilling more or less holes. An ebb and flow system can be designed by slowing drainage considerably, but this can cause water waste as the tank will still want to fill. The tank will fill and stop and the delayed flow will drain into the tanks overflow. Please build overflow protection into your chamber if you do this as the water will continue to flow through the grow chamber until the tank is filled unless it is diverted.

The Lid - Actually, it's the bottom of one of the bottles that has had a hole drilled through it to allow
the fill tube to be inserted.(Clear one in photo) It has also been cut from the bottle to
allow access to interior of the "grow chamber".

The Grow Chamber - The top of the 2L bottle. It is essentially a funnel. Acts as a mounting device
as well.

The Strainer - Essentially it stops the sprouts from falling through and in this case, dictates the
drainage rate. It could be a removable basket, which would allow for easier access
to sprouts. I will incorporate this into any future developments.

The Nut - A picture of myself would be quite appropriate here. In this case, however, it is simply a
bottle cap with the flat surface removed. It could also be used as a flow restrictor by
varying the size of the hole.

Step 5: Assembly

1. Thread fill tube through hole in lid so that the sprinkler end is inside finished bottle.
2. Invert strainer (green one) and insert into bottle top to form a basket at the bottom of the "grower".
3. Attach lid and secure, with tape, if necessary. The "grower" is now fully assembled.
4. Attach the "grower" to the bracket. In my case, I drilled a 1 inch hole through some plastic lid,
threaded the "grower" through the hole and secured it in place using the homemade nut.
5. Attach bracket to toilet tank as required. I used duct tape.
6. Fill with beans. Check for leaks and repair where necessary.
7. FLUSH AWAY

Mine appears to work beautifully so far. I had to drill drainage holes in the platform to allow for minor leaks and spillage. On that note, make platform recessed to hold minor leaks and spills. I was lucky as the lid already was.

Day two now and the Kidney beans you see in the pics have swollen and many have sprouted. The beans don't move without agitation. This may not be a problem, but if it is, it could be solved with a removable "grow" basket or with a modified fill tube. Water pressure is certainly not lacking in my case.