This modular hydroponic garden allows you to customize your system by choosing the components according to your personal demands. You can decide yourself whether to grow off the grid with the Kratky modules or to add modules that require electricity such as the Air pump and Light module. The different modules can be stacked on top of each other to make efficient use of your space. The majority of components are available at IKEA.
The different modules are:
Kratky Module (1 plant side), (1 plant middle) and (2 plants side)
The Kratky module allows to grow plants hydroponically without the use of electricity. The water uptake of the plant creates an air gap in the container which enables the roots to take up oxygen. If provided with a large enough container the initial application of nutrient solution should be enough for the entire cropping period, which is the case for crops that have low water consumption such as herbs and lettuce. Fruiting vegetables such as tomatoes and peppers have higher water consumption and thus require refilling the nutrient solution.
DWC stands for Deep Water Culture. It is a method of plant production by means of suspending the plant roots in a solution of nutrient-rich, oxygenated water. An air pump with air stone oxygenates the water. Providing the roots with high amounts of oxygen will result in higher yields.
This Module allows to sprout your seedlings before transplanting them into the hydroponic system.
With the light module, artificial light can be added if needed. It allows to give your plants a little extra or extend the growing season.
The Arduino module implements smart sensors into your garden that make it possible to monitor and control your garden with some help of smart technology.
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Step 1: Kratky Module
IKEA SAMLA 5L with lid
Net Pot 2 inch
Drill with 2 inch drill bit (51 mm)
Lid with one plant on one of the sides
- Use a Net pot and a marker to mark the area where the net pot will be placed on the lid. Make sure the net pot is placed just on the inside of the SAMLA box below, taking into account the wall thickness.
- Use the drill with the 2 inch bit to drill out the hole for the net pot.
- Place a small strip of masking tape +/- 5 cm on one of the sides of the container.
- Cover the SAMLA lid and box in spray paint. This prevents algae growth from light reaching the nutrient solution.
- After one hour, when the paint is dustdry but still flexible, remove the masking tape. Now leave the objects dry for 24 hours or according to the instructions on the spray can.
- Preparing the net pots.Make a cut at the bottom of the net pots, disconnecting the side ribs from the bottom. Do this for five of the ribs. Cut off the two bottom ribs. This allows the net pot to fit in the Samla box.
- Use scotch tape to connect the side with the bottom again to close the net pot. This is easiest done when the net pot is placed inside of the SAMLA box, since the shape of the box will force the net pot into a closed position.
Lid with two plants on each side
Follow the steps above but now drill two holes for the net pots on each side.
Lid with one plant in the middle
This module can be used at the top of your setup. Follow the instructions above but now drill a hole for the net cup in the middle of the lid. No adjustment to the net cup is required.
Step 2: DWC Module
2x IKEA SAMLA 5l with lid
Air pump that fits in the SAMLA box (28x20x14 cm), with 1-4 outlets
PVC tube that fit with the outlets of the air pump (6mm outside- 4mm inside diameter)
- 2 inch bit
- 0.25 inch bit (6-6.5 mm)
- Spray paint (optional to camouflage the air pump)
- Drill a 2 inch hole in the middle of the lid. This creates the opening for the plug and cable to enter the box through the lid.
- Drill a 0.25 inch hole at one of the sides of the lid. This is the opening for the PVC tube to enter the box.
- Optionally you can paint the lid and container to camouflage the content of the box.
DWC plant module
You can choose to have a planter module with one plant on one of the sides, two plants on each side, or one plant in the middle, similar to the lids in the Kratky modules. The only difference is the necessity of a hole in the lid to allow the PVC tube to enter the container.
- Follow the steps of preparing the lid and net pots as described in the instructions of the kratky module above.
- As an extra step, drill a 0.25 inch hole in the side of the lid as the opening for the PVC tube.
Step 3: Glasshouse Module
IKEA SAMLA 5L with lid
Fold the towel paper A few times until it has a few layers and fits the dimensions of the box. Make the paper towel wet and place the seedlings on top.
Step 4: Light Module
- IKEA SAMLA 5l with lid ( € 1.99)
- IKEA KOPPLA socket (€ 3.99 / 2 st.)
- IKEA TÄNDA clocktimer (€ 3.49 / 2st.)
- 2x IKEA Kvart clamp spotlight (€ 4.99)
- e14 CFL or LED growspots
- Drill with 2 inch bit
- Spray paint (optional for camouflaging the content of the box)
- Drill a 2 inch hole in the lid of the SAMLA as an opening for the cable plugs.
- Plug the spots into the clock timers and the clock timers into the socket. Place the whole in the container. The cables can exit through the hole.
- Clamp the spot on the front side of the SAMLA box.
Step 5: Arduino Module
Step 6: Additional Lighting
- IKEA FOTO pendant 25 cm (€ 9,99)
- IKEA FILLSTA tablelamp (€ 14.95) or plug cord with e 27 fitting
- IKEA TÄNDA clocktimer (€ 3.49 2st.)
- LED or CFL growspot e27 fitting
- IKEA Torkis Clothespins (€ 2,49)
- Remove the lamp shade from the IKEA FOTO pendant lamp.
- Remove the e27 fitting with cord from the IKEA FILLSTA tablelamp.
- Place the e27 fitting with cord from the IKEA FILLSTA tablelamp in the IKEA FOTO lampshade.
- Drill a hole and mount a hook in the ceiling or windowsill for the fixation of the lamp.
- Clothespins allow to re-position the height of lamp according to the growth of the plant.
Step 7: Nutrient Solutions
Here I share my method and knowledge of providing my plants with a nutrient solution. I learned this by checking information on the internet myself. Be aware that this is just one of the many possibilities and that a lot of other information is available on YouTube and other sources. Still I hope it provides you a basic overview of the topics involved.
I am using the 3 component FLORA SERIES nutrient solution from General Hydroponics. Plants need nutrients to grow. Nutrients can be divided into Micro and Macro nutrients. The separation of these different nutrients within the 3 component FLORA series allows to provide the plants with just the right amount of nutrients according to the growth stage of the plant.
Keeping things simple, there are three things important to consider when preparing your nutrient solution. These are the mixing ratio of the 3 different nutrient components, the pH level of the nutrient solution and the EC (electric conductivity) level of the nutrient solution which indicates the amount of particles dissolved in the water.
The second image above shows a growing chart provided with the flora series nutrient solution. The chart distinguishes different growth stages, such as: Seedlings, General purpose, vegetative and blooming. As explained before, to get optimum yields, the plant needs different nutrients at these different stages. The Kratky method however, which is the simplest method of hydroponics, allows you to grow without the necessity of changing the nutrient solution. For herbs, lettuce and other crops that do not consume lots of water to grow, an initial filling of the 5L container with a nutrient solution should be enough for the entire cropping period. For fruiting crops that require a bigger amount of water such as tomatoes and peppers it will be necessary to refill the container with nutrient solution. Keep in mind that for the Kratky method (that does not include an air pump) an air gap within the container will be necessary to provide the roots with oxygen. So only refill the container half way.
The "general purpose" mixing ratio (see grow chart) of 1:1:1 for the three components is used. This means mixing 1,32 ml of each of the components per liter water.
More advanced growers can vary the mixing ratios according to the different growth stages of the plant. See the grow chart for instructions.
The ability of the roots to uptake nutrients from the solution is depended on the PH value of this solution (see third picture, pH chart). The optimum pH range, where the plant is able to uptake all the nutrients, lies between a value of 6 to 7. The pH of tap water varies regionally. Also the amount of nutrients dissolved in the water will influence the pH value. Therefore it is important to check and adjust the pH value of your nutrient solution before the solution is provided to the plant. A liquid pH test kit can be ordered (cheap but less practical option) or an electronic meter (expensive option) can be purchased for checking the pH. When the pH value is either too high or too low you can adjust it with a pH up or pH down solution that can be ordered. An overview with specific pH values per crop is given in the images above.
The EC value tells you something about the amount of particles dissolved. Sometimes this can also be provided by a cF of PPM value. Plants need nutrients to grow, a shortage or excess in the amount of nutrients provided can restrict this growth. Therefore it is important to check the EC value with an EC meter, and adjust to the optimum value if necessary. See the table provided in the images above for the specific EC value of different crops.
Participated in the
Indoor Gardening Contest