A 12 Litre No-Tech Aquarium Filtered by Umbrella Papyrus

I have recently installed a 12 litre aquarium on a large window ledge in my flat. Inspired by a low-tech aquarium project I have seen in the web [1], I wanted this aquarium to run without any means of technical equipment (no-tech).

12 litre no-tech aquarium on my window ledge.

As the window is facing southwards, the aquarium receives high amounts of sunlight during summer. At this point I am not sure whether the intensity of the sunlight will be enough to allow for plant growth during winter.

I didn't install a heater in the tank, thus the water temperature is subjected to relatively high fluctuations, currently (summer 2012) ranging from 16 °C to 34 °C, with a mean temperature of about 24 °C during the day.


With respect to water filtration - of course the tank has to do without an active filter - I decided to plant Cyperus alternifolius in the tank. This plant, which is also called umbrella papyrus, is native to Madagascar, but due to its neat appearance yet modest growth requirements is used worldwide as an ornamental houseplant. Interestingly, not unlike many other marsh plants, the umbrella papyrus seems to effectively remove organic pollutants (nitrogen, phosphorus) and also heavy-metals such as copper from the water phase [2, 3]. Therefore, it may be used to purify domestic or agricultural wastewater, but also aquarium water.

Cyperus alternifolius

  
Although it is usually difficult to provide stable water conditions in small volumes such as 12 litre, I hope that the umbrella plant in the long run will be able to keep the nitrate and phosphate levels down to a minimum. I planted it in quartz sand with a height of approximately 2 cm, and already after 2 weeks it has established a dense meshwork of roots within and above the sand.

Roots of Cyperus alternifolius, all newly formed within 2 weeks.

1. www.tuncalik.com.
2. Yuanxiao et al., 2002: Purifying Efficiency of Cyperus alternifolius to Domestic Sewage and Its Application in Constructed Wetland. Chinese Journal of Applied and Environmental Biology.
3. Liao et al., 2005: Comparison of nutrient removal ability between Cyperus alternifolius and Vetiveria zizanioides in constructed wetlands. Ying Yong Sheng Tai Xue Bao, Vol. 16(1), p. 156-60.