Mini Kratky Jars - Easy Hydroponics
Introduction: Mini Kratky Jars - Easy Hydroponics
UPDATE 12 APR 2021:
A second new design has been completed that further addresses determining the water level and adding additional nutrient solution.
Even with the new wide mouth non-threaded lid it was not easy to add nutrient solution without spilling and seeing the water level was still difficult so I added an automatic water level indicator.
The water level indicator is visual and will indicate when water level reaches the bottom of the net pot and also when the the jar is fully topped off (this is about halfway up the net pot), which makes it super easy to simply add water directly into the net pot and know when to stop. This drastically reduces the chances of spilling.
See Step 12.
END UPDATE 12 APR 2021.
UPDATE 12 DEC 2020:
So I had a lot of trouble getting plants to grow past the seedling phase. They'd germinate just fine and send roots down into the liquid, but wouldn't continue to grow. The problem was with the jars being in the window sill and absorbing too much infrared energy. Once I realized this may be the problem I used a laser thermometer to check the temperature of the glass. It was almost 130F! D'oh!!
CAUTION: If placing in windowsills - Use cloth, cardboard, etc. to shade the jar to prevent solar energy from overheating the glass/nutrient solution/root system.
I also made a few modifications to the 3D printed lid design. Based on these findings:
1. The soda bottle cap turned out to be a real pain. You have to have both hands free to remove or install it, which made topping off the nutrient solution quite a chore. The hole was too small to be able to see where the water level was, which also made it difficult to add solution without spilling. The new design removes the screw on soda bottle cap and replaces it with a simple press in lid that also has a much larger opening.
2. The bamboo skewers being inserted into the net pot was a poor design. Once the plant got large enough to need the skewers for support, the weight of the plant would simply tip the whole thing over. (Since there is nothing to hold the net pot to the 3D printed lid.) As a result of this, I added skewer holes into the 3D printed lid.
See newly added Step #11 for the revised design.
END UPDATE 12 DEC 2020. (original post starts below.)
Project Summary: Unique way to grow small plants hydroponically according to the Kratky Method, using Net Pots, Clay Pebbles, Rock Wool and a Custom 3D Printed Part I designed in Fusion 360. (Perfect for herbs on a kitchen windowsill.)
This project is an entry in the Mason Jar Contest. 440
Please vote if you like it.
So, I had several ideas for the contest, but in doing research for one of them, I came across the Kratky Hydroponic Method. I don't know how I haven't heard about it before now. Its extremely cool, and I'll be learning more about it as I continue experimenting with it. The coolest part is it requires NO ELECTRICITY!
Here are a few good links to get you started if its new to you as well:
* https://en.wikipedia.org/wiki/Kratky_method
* https://patents.justia.com/inventor/bernard-a-krat...
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Supplies
1. Pint Size, Wide Mouth Mason Jars
2. Rock Wool 1" Cubes
3. Clay Pebbles
4. 2" Net Pots
5. Bamboo Skewers
6. Soda Bottle Caps
7. Hydroponic Fertilizer Solution
8. Seeds or Seedlings (Your Choice)
TOOLS:
1. 3D Printer
2. Sharpie Marker
Step 1: Kratky Method Primer
Here's a brief explanation of the technique developed by Dr. <PERSON> of the University of Hawaii.
(Image above is from the Youtube Video from Epic Gardening linked on the previous step.)
* As the seedling grows it sends roots down into the nutrient rich water. As the roots develop, and the plant grows, eventually, the water level will drop, and the plant will use the portion of the roots that are submerged in the water for hydration and nutrition, and the portions that are in air to supply oxygen.
To maintain plant growth simply continue adding nutrient rich water but only to the lower level of the container. (Never completely submerge the entire root system. 389