Constant oxygen release and nitrogen uptake rates by plant roots were taken from Samsó and García (2013) (3 gO2 m− 2 d− 1 and 0.2 gN m− 2 d− 1, respectively) and apply to the top 30 cm layer of the granular media. Passive diffusion of atmospheric oxygen into the water body is also considered in BIO_PORE (see Samsó and García (2013)).