When you choose Hydroponics/ Soil-Less method to grow plants. It's always two types of systems you will find. Open system and closed system.
Open system is like the pot or any container that you use to grow a plant, where you let the water go out or get drained but do not reuse.
Examples: Pots, Grow bags, microgreens or vegetable trays.
On the other hand, there are systems which enable us to reuse the water or nutrient rich water.
Examples : NFT (Nutrient film technique) system, or (DWC) Deep water culture. I will provide a detailed understanding about these systems in another post.
In closed systems you can save lots of water, upto 90% and nutrients, as the mineral rich water is recirculate back to feed the pants. And you can grow more in lesser space as they can be connected to each other and arranged vertically.
In open system nutrient usage will be more and there could be loss of water due to draining and evaporation etc.
Though closed systems are very efficient with respect to saving water but there is one major disadvantage. If plant roots get infected it will be easily spread to all the plants as the same water is being circulated throughout the system.
However there are different ways to deal with that. We will discuss that eventually.
In open system that risk is minimal. If anything goes wrong with one plant that does not affect other plants as the roots are not at all linked with each other. Each of them are independent systems.
Click here to watch the video on same topic
Hope this gave you a usefull information to understand what are main categories of growing systems in Hydroponics.
Co-founder, farmer and coach