We build a simple „DWC - Deep Water Culture System“ . Sounds more complicated than it is.
What is needed:
Drill 4 - 6 holes into the removable lid, depending on the size of the tank. The holes must be large enough to hold the net pots, but not to slip through them.
To convert the box with the lid and the net pots from a passive to an active system, you need an aquarium air pump with aeration stone (Internet approx. 20 Euro). If you want to use the tank indoors, please make sure that the pump is as quiet as possible. The aeration stone is placed in the tank as an oxygen supplier. The best way to control the air pump is to use a timer. DWC is by the way a very effective, simple system, with which you can get familiar with the hydroponics very well. You easily can try different things.
Now you just have to put the prepared plants into the net pots and insert the net pots into the holes of the box. Add water to approx. 1 cm above the lower edge of the net pots and add hydroponic fertilizer according to the manufacturer's instructions.
Switch on the pump via the timer every 30 minutes for approx. 10 minutes - this supplies the roots with oxygen. Attention: Only immerse in water if all electrical consumers are disconnected - Observe and follow the manufacturer's instructions for the air pump.
After one day, measure the pH value and adjust if necessary. For this you can use pH-Up, if the water is too soft, or pH-Down, if the water is too hard.
From time to time measure and adjust the nutrient content with the EC-Meter. We only do this about every 2 weeks - but it also depends on the nutrient consumption of the plants.