One kilogram of fresh aquatic plant biomass contains 1 gram of phosphorus. As phosphorus is the limiting element for algae growth in an aquatic ecosystem, we can say that collecting and composting 1 kg of withered water lily leaves and flowers exports 1 g of phosphorus out of the biological pool ecosystem. In theory, this gram of phosphorus could contaminate 10 m3 of water in such a way that algae could start to cloud the water.
Collecting water lily leaves could make sense from the third year onwards, because before they usually do not reach the speed of leaf production that justifies this action.
The collection of water lily leaves is easy and could be done by hand, from the separation wall, with a floating plastic container within reach. Many leaves grow near the underwater barrier between the plant zone and the bathing zone. Take out the leaves that start to turn yellow, these loosen the entire stem more easily. Of course, the more withered ones are also removed. Next, the water lilies show all their beauty and their beautiful and vivacious appearance after this intervention that justifies the work.
As the photo shows, in larger biological pools you can work even better from a boat or kayak, which allows you to reach even the furthest water lilies. The photos show an action of collecting water lily leaves in the biological swimming pool for tourist use at Herdade dos Adães, Campo Maior.