Redfield ratio

The Redfield ratio ( engl. " Redfield Ratio" ) describes the proportions of the atomic composition of marine phytoplankton.

The 1963 by Redfield, Ketchum and Richards empirically discovered and published ratio is:

1 mole of P: 16 mol N: 106 mol C

This means that in unlimited available nutrients contains the plankton per one mole of phosphorus, 16 moles of nitrogen and 106 mol of carbon.

The importance of the Redfield ratio for oceanography and marine biology stems from the fact that plankton is the basis of ( indigenous ) food pyramid.

Calculating with the Redfield ratio

= 3550 g · mol -1

After Redfield occur during fertilization with 1 Kg phosphorus ratio (atomic mass = 31 g · mol -1) 114.5 Kg biomass

32.26 mol · 3550 g · mol -1 = 114 516 g = 114.5 kg

Applicability in aquatics

Today, the Redfield ratio is increasingly used in the aquarium hobby to overcome a green or blue-green algae infestation biologically. For this purpose, the minimum factor by measurement of nitrate and phosphate, the ratio should be in the "green zone " 15-30, added as potassium nitrate or potassium phosphate.