The experiment was the Winogradsky column. We are a two person team from the University of Thessaly, Greece. The experiment was held in Volos in the region of Anavros. We used a plastic bottle (1,5L), seawater (~500ml), an egg, pieces of newspaper and an amount of sediment from the beach.
After ten days we can see the water changing color and becoming yellow.
In this image of the column we can see the colour of the water changed in to bright pink. This is a result of the existanse of Calcium from the egg shell. The sediment begins to becοme black.
We can see that the colour became dark purple and the sand sediment became black because of the anaerobic conditions in the column and the light.