The Zulauf Ag located in Schinznach Dorf is one of the largest tree nurseries in Switzerland. The company, existing since 1879, reached a size of 30 ha and contains nowadays more than half a million plants (Zulauf AG, 2018). The tree nursery has a cycle within their irrigation system. The irrigation water which isn’t adsorb by the plants infiltrates directly or after leaking from the plant pots into the ground in whom the water is collected by an impermeable interlayer and guided to a pond. From this pond the water will then again be gathered for the irrigation only running through broad filter. External water is only needed to compensate the loss through transpiration and is drawn from the groundwater as Johannes Zulauf has told. Within the irrigation system are several spots which are interesting for a research related to the microorganism community. One of those is the pond. As Mr. Zulauf told the pond use to be 30m deep but as recently discovered it has been filled by sediments ...