Part I · Understand
The basic principles of hydroponics
Without soil, there is no buffer: everything the plant gets comes from you. Water, nutrients, oxygen: the three constant needs.
In the ground, soil stores water, holds on to nutrients and cushions mistakes. In hydroponics, the roots receive a nutrient solution directly: water in which everything the plant needs has been dissolved.
The growing medium (rockwool, coco coir, clay pebbles) does not feed the plant. It holds the plant and provides an interface between water and air.
Three needs, all the time
- Water: continuously or in cycles, never a prolonged dry spell.
- Nutrients: a complete solution (macro- and micronutrients), at the right concentration (EC) and the right pH.
- Oxygen: roots breathe: a thin film (NFT), trickling flow (tower) or aeration (DWC).
A fast system… both ways
A pump failure, a pH or EC drift, water that gets too warm or a root contamination can hit an entire system within hours. So the design should favor simplicity, access, cleaning and redundancy.
Choosing the system for the plant
| Criterion | Vertical tower | Horizontal NFT | Growing medium + drip |
|---|---|---|---|
| Leafy greens / herbs | Excellent | Excellent | Good |
| Strawberries | Promising | Possible | Very well suited |
| Tomato / cucumber | Poorly suited | Poorly suited | Suited |
| Density per floor area | Very high | Medium | Low to medium |
| Sensitivity to pump failure | High | High | Variable |
| Cleaning | Moderate | Easy | Moderate |
Frequently asked questions
What is hydroponics?
It is growing without soil: the roots sit in, or are watered with, a complete nutrient solution. The growing medium (rockwool, coco coir, clay pebbles) holds the plant up but does not feed it.
Which plants should I grow hydroponically as a beginner?
Leafy greens and herbs: lettuce, arugula, basil, parsley, bok choy. They grow fast and do just as well in towers as in NFT or with the Kratky method.
