Abstract: The disclosure relates to a filtration system for harvesting microalgae. The filtration system includes a filter housing with modular filtration units each containing a fungal filter. The fungal filter includes a perforated support with a capture fungus on the support. The fungal filter is adapted to be removed and replaced from the modular filtration unit, for example during operation of the filtration system. The capture fungus is adapted to capture one or more types of microalgae upon contact of the capture fungus with the microalgae, for example via fungal mycelium. During use of the filtration system to treat an influent stream containing microalgae, microalgae are captured and coated on the fungal filters. The coated fungal filters can be easily removed and the microalgae is harvested directly from the perforated support. New replacement filters can be inserted into the filtration system for continuous operation.