The first is nursery culture of the wetland macrophyte, Pontederia cordata , from seedlings to 3 month old plants.
Agricultural wastewater is provided in the nursery as a nutrient source to support plant growth.
The second technique is periphyton filter technology. Periphyton filters utilize intensively cultivated and harvested attached algae, microalgae and microorganisms grown in a raceway. The two systems were operated under different conditions. Periphyton filters operated well during cooler weather. Periphyton filters are thus superior to P. cordata both in terms of amount of P removed and achievement of low levels of P in the treated water.