Gravel
The same kind that is used for aquariums – even though any kind of gravel can be used, as long as it is washed before. Indeed, many plants are cultivated with the hydroponic method that uses gravel.
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The plants grow in a typical gravel-filter bed, in which water is circulated by the aid of electronic powerhead-pumps. Gravel is cheap, easy to keep clean, good to drain and cannot be set underwater.
But gravel is also very heavy, and in case, that the system does not supply water continuously, the plant roots run dry.
The plants grow in a typical gravel-filter bed, in which water is circulated by the aid of electronic powerhead-pumps. Gravel is cheap, easy to keep clean, good to drain and cannot be set underwater.
But gravel is also very heavy, and in case, that the system does not supply water continuously, the plant roots run dry.
