How does it work?
Hydroponics gardening is based on replacing the soil in regular gardening with just water. The water contains all the nutrients the plant needs - so the roots don’t need to be so aggressive in their growth to find those nutrients. This means the plant can redirect it’s growth to the plant itself in the form of leaves, stalks, fruit and vegetables.
How is this done?
Basically the plants are placed in either vertical columns or horizontal trays.
With the vertical grow method, plants are either put into net pots and inserted into a vertical column, or they are placed into a cloth and inserted into the column directly. I find using pots much easier and more convenient. The plants are irrigated by pumping water to the top of the column and dripping down onto plant roots. This is a gravity-fed system.
With the horizontal method, plants are potted into net pots or other pots that allow their roots to grow beyond the pot and into the water in the tray below. The plants are irrigated by flooding the lower tray. Lighting is usually installed underneath the shelf above. You can get a lot of plants on a simple shelving unit with four shelves. Growing trays are great for herbs, salad greens like lettuce, kale and also for microgreens.
Other methods include using mister or dripper to slowly feed water directly onto plant roots. The number of plants in a vertical system will be limited by height. Industrial applications have very tall columns that are impractical for home use. A good home system should have capacity for at least 24 plants. Vertical grows are good for larger plants like bigger lettuce, prolific herbs like basil, mint, and vegetables like cucumber, eggplant and even small tomatoes.