Here is a collection of material suggestions that make sense for a hydroponic system.

This is intended to be just a cost-effective selection and an inspiration for what is needed at least for a small home system. When it comes to the size of the system, we base ourselves on around 20 tomato plants, which can then be placed in the system with the appropriate minimum distance. Depending on the plant, the space required in such a pipe system with NFT technology is 15 to 50 cm between the individual places. Since the roots in a hydroponic system require significantly less space than in outdoor cultivation, you can - as a rule - orientate yourself on the space required by the plant "above ground". For 20 tomatoes, each with a space requirement of 50 cm, you get a system (pipe) length of around 10 meters. This means that each plant has 25 cm of space, calculated from the root. The holes for the plants are 50 cm apart from each other.

KG sewer pipe DN 125, length: available in 2m and 1m

The sewer pipes and fittings made of hard PVC require no care or maintenance. 

Due to the design (i.e. the material used), the pH value, which can become very acidic, does not play a role. The original intended use also tolerates aggressive concentrations. These pipes are designed for use on farms, among others, and are resistant to strong acids and alkalis.

Diameter: 125 mm
Material: hard PVC
Color: orange
Acid and base resistant
For house and yard drainage
Outdoor use

In the hardware store from €8.45
Length: 2.0 m (€4.23 running meter)

KG elbow DN 125, 87.5°

The sewer pipes and fittings made of hard PVC require no care or maintenance. The extensive range ensures optimal customization options for the planned system. 

Diameter: 125 mm
Material: hard PVC
Color: orange
Acid and base resistant
For house and yard drainage
Outdoor use

In the hardware store from €2.95

Hole saw/cup drill

Diameter about 10 cm

The diameter depends on the plant; for tomatoes we used a 10 cm drill. Most pots do not fit exactly into the hole or are not completely light-tight. Paying attention to this reduces algae growth somewhat. We recommend buying the pots a little larger, i.e. over 10 cm in diameter, and cutting them open on the side. Thanks to the overlap, the pot can then be inserted exactly into the opening.

In the hardware store from 15 € 

Aquarium pump

1200 liters / hour,  sufficient for around 40 plants

In order to continuously supply the plants with running water (the nutrient solution), you should pay attention to the slope of your system. Here you have to find a compromise, because the following requirements conflict with each other: The incline or gradient of the pipes used - i.e. the difference in height from the inlet (the feed) to the outlet - should be around 10 cm per meter in order to achieve a high flow speed . That's a 10% gradient (at 90 degrees maximum: 1 meter gradient on 1 meter stretch is 100%). This promotes turbulence and thus the oxygen content in the nutrient solution. 

With this specification, the difference from the lowest point of the system to the highest is 10 cm per meter: For a 10 meter long system, that is a meter difference in height. If you add a collecting container with a height of 30 cm, the plant and the last seedling end up at around 1.3 meters. If you plan tomatoes, you will need a ladder to prune and harvest the plants. 

You can further reduce the incline or gradient of the pipes used, but you should then expect slightly lower harvest results.

In hardware stores from €35

Rain barrel / wide-mouth barrel 120 liters

The reservoir used should definitely have a label that identifies the material as food safe. In the example system discussed, we use an intermediate storage unit, which requires a second pump. This is unnecessary for smaller systems, but it does force you to check the nutrient content daily depending on the weather. During hot days, terminal tomatoes consume about 1.2 liters of water per day (in an open system). The problem: with increasing evaporation through the leaves, the pH and Ec values ​​increase. Depending on the plant and the amount of nutrients used, this can lead to undesirable effects. To find the right barrel (whether blue or not) you should take a look at the plastic types. Here is an article about it.

From €35

Flower pot, plant support

Commercially available flower pots are very suitable as “pots” because they do not decompose as quickly in the sun and are inexpensive. We recommend slightly larger pots for planting. They should be slightly larger than thatHole in the pipe because they fit so well at the edge. In order to fit the pots precisely into the opening, you can cut them open at the edge. The cut goes to the middle of the bottom of the pot. This allows you to overlap the edges and the tension of the pot allows an almost completely tight fit into the hole in the pipe. In the example picture we use coconut fibers as filling material. These are weatherproof enough to be used multiple times. To make it easier to remove the roots from the coconut fibers, simply place the cut root balls in the sun for a few days. This means that the dried roots break down and the coconut fibers can be used again. But: not all roots are suitable for coconut fiber as a soil replacement. Coconut fibers are very suitable for our example plant with tomatoes. You can get coconut fiber as “nesting material” at hardware stores or pet stores. Considering that it is a waste product of coconuts (the shell), the price is surprisingly high. Do not buy the fibers in small quantities or you will pay exorbitant amounts. On internet trading platforms you can get the kilo from around €30. Search for "coconut fiber, craft supplies, decoration and nest building ." Why not rock wool? The rock wool breaks down and this "rock hard" material wears out the water pump impellers - if you use a pump of this type. Rock wool is also not as easy to reuse as coconut fiber, not to mention the CO _{2 footprint.} But you decide what suits your system best.

 Kontext: 

• 3) Die blaue Tonne aus dem Baumarkt
• 2) Materialauswahl
• 1) Konzept einer Hydroponikanlage
• 4) Messen, Steuern, Regeln
• 4) Measure, control, regulate
• 1) Concept of a hydroponic system
• Anlagenvergleich nach Kosten/Nutzen
• Wärmedämmung Übersicht
• Umwälzpumpe
• Energiekosten
• Eigenbau
• 3) The blue bin from the DIY store