Graduated Kratky Hydroponic Planter

thingiverse

This graduated Kratky (non-circulating) hydroponic planter is perfectly suited to growing greens such as lettuce, spinach and bok choy. Simply start your seedlings directly in coco coir, inside a standard 2-inch net pot in half-strength hydroponic nutrient solution, and pop them into the planter (filled to the 4 L mark) when you observe the first true leaves. The lower 1.5-2 centimetres (a little over half an inch) of the net pot will be immersed into the nutrient solution and the coco coir will be kept moist by capillary action. It's truly a set and forget project until you harvest your greens! The graduations on the inside of the planter make for easy preparation of the full strength nutrient solution (usually given in terms of quantity of fertilizer per 4 L of water). When using the non-circulating hydroponic growing method, care must be taken not to overfill the container when refilling the planter (when growing dwarf cherry tomatoes, for instance). This precaution is needed to avoid drowning the delicate air roots that develop as the plant's roots reach deeper into the dropping nutrient solution over the course of the grow. You should then never refill above the 2.67 L mark (2/3 of the initial 4 L of solution). Although I did not 3D print the design yet, I designed it to avoid/minimize the use of supports. As it is important to use the proper settings to ensure watertightness of the planter, users should consult the following links for best results: - https://www.instructables.com/3D-Printing-Make-Water-Tight-and-Air-Tight-Contain/ - https://blog.prusa3d.com/watertight-3d-printing-pt1-vases-cups-and-other-open-models_48949/ For more information on the non-circulating hydroponic method, please read the following article from Dr. Kratky: - https://www.ctahr.hawaii.edu/hawaii/downloads/three_non-circulating_hydroponic_methods_for_growing_lettuce.pdf The wicker basket texture was taken from ambientCG.com, licensed under CC0 1.0 Universal and can be found at the following link: - https://ambientcg.com/a/Wicker004