All You Need to Know - Understanding Hydroponics Systems

Hydroponics is regularly used by growers around the world to produce fast growing crops with a high yield. Although the name sounds quite high tech and modern, soil less growing has been around for centuries, researchers as far back as the 18th century realised that soil itself was not essential to plant growth. In plant growth soil is simply a medium or reservoir, something to hold the nutrients that the plants need to grow, This method replaces the use of soil with other mediums such as rock wool, coco scuff or pebbles. Replacing the soil with other mediums has many benefits as it allows the grower to be in total control of not just what nutrients are available to the plants but when, in soil growing it takes a very experienced gardener with a keen eye to know just how much nutrient a plant might need and how often, with hydro-systems the nutrient can be closely monitored using meters to measure the CF (salt minerals content) and the PH (acidity) all which are vital to premium plant growth.

There are many different types of hydro systems used today, much research has been done to advance the science of hydro gardening into a simple but effective growing system that can grow pretty much any many plant to great success. With a little know how and some simple materials available at most DIY stores it is possible to make a Hydro system but before we get into that lets have a brief look at the ready made systems available and how they work.


Nutrient Film Technique is amongst the most commonly used hydroponic systems.

To set up an NFT system you would need:

    Purpose built trays or gulley’s to sit the plants on.
    Reservoir or tank to house the solution
    Submersible pump and piping system for irrigation.
    Spreader mat.
    Growing Medium

nutrient film technique

So how does it work? Plants are suspended in a medium, most commercial growers use rockwool blocks for this but baskets of clay pebbles are also favoured. A nutrient mix of specially formulated liquid fertilizers is mixed in the tank (A) because the solution is based in clean water there are a lot of basic enzymes missing from the solution, these are added separately usually in liquid form, there are many different brands on the market and experienced growers tend to have their own formula or mix, this is often a closely guarded secret as the correct solution mix with the correct enzyme additives can make a huge difference to the final yield of the plant. The solution is circulated from the tank using the submersible pump(B), up to the growing tray and is pumped in at the top (C) the nutrient solution then runs down the tray(which has a layer of spreader mat on top) creating a film of nutrient, this is known as nutrient film technique. As the film runs down the trays the nutrients pass over the roots of the plants (D), the solution then falls back into the tank (E) to be re circulated back to the plants. Some growers use the same system but only pass the nutrient solution over the plants once; this is known as Run to waste NFT.

Flood and Drain

To set up a Flood and Drain system you will need:

    Purpose built trays or gulley’s to sit the plants on.
    Reservoir or tank to house the solution
    Submersible pump and piping system for irrigation, with one way valve.
    Growing Medium

flood and drain

Flood and Drain is a passive system as is NFT but there are differences in how the solution is delivered to the plants. The nutrient solution is mixed in a tank (A). As we have seen above NFT provides a film of nutrients that passes over the roots to allow them to absorb the solution, with Flood & Drain the plants are set in the chosen medium and then they sit in the tray or gulley without any solution, the nutrient is usually pumped up to the trays or gulley’s from the tank using a submersible pump, not all F&D systems use a pump some are gravity fed but either way the mechanics are the same.

The pump will allow the trays or gulley’s to be flooded with a predetermined amount of solution through a one way valve(B) but unlike like NFT or other passive systems the solution is held in the tray or gulley for a time to allow the medium to soak up the solution and feed the plants(C). The solution then drains slowly back into the tank and the process starts again.

Dripper System

To set up a Dripper system you will need:

    Purpose built trays or gulley’s to sit the plants on.
    Reservoir or tank to house the solution
    A timer controlled submersible pump and piping system for irrigation,.
    Growing Medium

drip system

As with all the systems we have looked at so far the dripper system has a tank to store the ready made solution (A). The solution is pumped up to the growing area using the submersible pump (B) but with this system the pump is timer controlled with flow controls added to the irrigation pipework (D) to allow a predetermined amount of solution to be delivered to the plants (C), this time rather than run down the tray in a film or as a flood the solution is dripped directly on top of the medium(in this case Rockwool is used) and over the roots of the plant, it then makes its way back to the nutrient tank and the whole process starts again (E).

Deep Water Culture (floaters)

To set up a Deep Water Culture floater system you would need:

    Purpose built pots to sit the plants in.
    Polystyrene Floater boards
    Reservoir or tank to house the solution
    Growing Medium

deep water culture

A deep water culture system is pretty similar to a standard flood and drain system, a tank is filled with a premixed solution, the plants are sat in a pot with a medium for support and to absorb the solution. The pots are inserted into a polystyrene floater board which keeps the pot floating on the solution rather than sitting on a tray or gulley. Smaller growers would  empty the tank manually periodically but larger growers would adapt the flood and drain system to automate the delivery and drainage system. An air pump is defiantly needed in this system as the roots tend to be totally submerged within the solution so will struggle for oxygen, as we will see later on oxygen is vital to all growth whether its hydro or soil based.