June 2023
Details on small desktop USB-powered hydroponic system.
The world of gardening is vast, ranging from the simple act of planting a seed in moist soil and waiting for it to sprout to the use of advanced techniques such as fog makers placed beneath the root system. Personally, I enjoy growing my own food as it feels like I am printing my own money without breaking any laws. I have a detached garden outside my apartment where I tend to my beds, apple trees, and berry bushes. Unfortunately, due to the mild climate, I can only use it for about 6-7 months, with only 4 of those being warm enough for optimal growth. To continue growing plants year-round, I have started exploring hydroponics, which is a cleaner and more practical option for indoor gardening. Hydroponics is a vast field, but it can be simplified into two categories: passive and active systems. Passive systems are straightforward, and you may have seen self-watering pots as an example. Instead of soil, I prefer to use materials like coco coir, which is both inexpensive and readily available. This material is a byproduct of coconut processing and is often marketed as an eco-friendly option. Active hydroponic systems, on the other hand, are the cool-looking fountains and flowing water features that people typically associate with hydroponics.
I've opted for the ebb&flow hydroponic method for this build, as I have previous experience with this system from my larger container-based build. The primary difference in this build is the size and the use of USB-C electronics. While I usually utilize a simple smart plug and standard fountain pump, this method would be excessive for the scale of this system.
This hydroponic style is cost-effective and straightforward, considering the amount of water and fertilizer utilized throughout the growth cycle. The basic principle involves a reservoir with water and a growing medium regularly flooded with fertilized water and then drained back into the reservoir, allowing the roots to absorb nutrients while exposed to air between cycles. However, this process necessitates timing. The most basic and traditional approach is to use a constant pump that floods the container with a bell siphon installed, the flood time is determined by the pump's flow rate and the bell siphon's height. This is a common practice in commercial applications due to its low maintenance.
Another option I frequently use is a pump with a timer, either a smart plug or a MOSFET timer, located in a spot like HydroKUGGIS.
When practicing hydroponics, the absence of soil necessitates the provision of appropriate support for the plant roots to prevent them from collapsing during growth. In ebb&flow systems, there are different options available for root support, like plastic net cups or coco peat. Each medium has its own advantages and disadvantages, but the main point to consider is proper drainage and aeration. Although net cups may seem perfect due to their excellent drainage, they lack root protection since the roots are directly exposed to air, leading to root dehydration. Also, if the timer fails, there's only limited time to fix the situation. Conversely, coco peat is not the best choice since it retains too much water and inadequately aerates compared to other media. It is important to note that there is no one-size-fits-all solution, and some experimentation may be needed. For instance, some people use large trays with glass fiber blocks that simply rest in place.
I personally find using those blocks to be quite expensive and difficult to reuse for different needs. However, I highly appreciate the concept of having each plant in its own container with its unique growth medium. This arrangement allows for swift plant replacements and efficient harvesting and I plan to create a similar system with this approach.
From my personal experience and experiments, I have discovered that expanded clay pebbles, also known as keramzit in Czech, are my preferred choice for a growing medium. These pebbles are affordable and can be easily found in local hardware stores. Interestingly, they are often used as decorative coverings for soil in potted plants. In hydroponics, expanded clay pebbles are widely used due to their documented behavior, such as their ability to change water pH and EC levels. Additionally, they provide moisture retention and excellent aeration for roots, making them an ideal option for plant growth.
Perlite is another excellent option that offers similar advantages to clay pebbles. It should be noted, however, that perlite may be less readily available and could be more expensive if purchased in smaller quantities. Additionally, due to its white color, it has a higher likelihood of developing algae buildup.
I’ve chosen the IKEA KUGGIS boxes as a base and reservoir. Many people are already using larger versions for DIY DWC, Kratky, or similar ebb&flow systems, and in my opinion, it looks a little bit better than IKEA TROFAST.
You will need two KUGGIS boxes 18x26x8cm, one lid, and the main inlet, print all parts from the attached 3MF file, at least 3 perimeters but some parts are really small.