Microbiological contamination of the target
plants is not a problem discussed in aquaponic
literature, as the harvested crops have only contact with the fish water by their root system.
Nevertheless this topic should be addressed, as
heterotrophic plate counts revealed similar concentrations in salmonid farm effluent (105
CFU/
ml [9]) as in mechanically pre-treated municipal
wastewater (106
CFU/ml [10]). In case hydroponics are used to recycle nutrients from municipal wastewaters, this topic is of primary
importance. In this case, pre-treatment with
planted sand filters followed by UV radiation
should be considered [11]. This approach was
already tested; lettuce and capsicum indeed are
able to utilize nutrients from municipal wastewaters [12].