So the next thing we had to figure out was how we could remove the oxygen, which we did by building this column which circulated some of the water, and put back CO2, which we did by bubbling the system before we recirculated the water.
Assim, tivemos de imaginar como podíamos remover o oxigénio, o que fizemos criando esta coluna que circulava parte da água, e repondo o CO2, o que fizemos, pondo o sistema a borbulhar antes de fazer circular a água.