Your First Transplant
Now that your seedlings have outgrown their clear plastic tote growing chamber, it's time to transplant them into their own accommodations. At this stage of growth, I like to move the seedlings into plastic mason jars.
I use a hole saw drill bit on my drill to create perfectly sized holes in the plastic mason jar lids. Then, I add enough hydroponic solution to the mason jar so that the bottom of the rockwool cube is submerged in the nutrient water.
This is the hole saw attachment I used to drill holes in my mason jar lids. Try to position the holes as close to the center as possible. The 2-1/8 inch size is ideal for 55 mm net cups, which should fit snugly into the lid. For readers using metric, 16 fluid ounces is roughly equal to 500 ml.
The roots will naturally absorb the water and nutrients, growing downward as the water level decreases. You might wonder: Do you need to cover the mason jars to prevent algae growth?
Typically, algae growth is only a concern in the containers where the plants will reside permanently. These mason jars are temporary housing, and the plants will outgrow them and require another transplant before algae becomes a problem.
You can spray paint the clear mason jars black or cover them with tin foil if you prefer, but I don't think it's necessary.
For suitable containers, I recommend these 16-ounce plastic mason jars. They are lightweight, easy to drill, and ideal for this stage of your hydroponic setup.
Coming Up: The Kratky Method
In the next chapter, we’ll be discussing the Kratky method of hydroponic growing. This is a power-free way to grow hydroponically—no aquarium pump needed.
As the nutrient water levels drop and need to be replenished, you simply add more water to the tank, but not all the way to the top. When the water level decreases, the roots that form in the gap between the nutrient solution and the lid become “oxygen roots.” These roots absorb oxygen directly from the air, replacing the role of a pump that would normally aerate the water.
The bottom line? You can skip the water pump entirely by filling the container only halfway with nutrient solution. We’ll go into more detail on how this works and how to implement it effectively in the next section.