An aquarium filtration and algae control system, for use with an aquarium containing a quantity of water, having a housing having a growth chamber and an overflow part. The growth chamber includes at least two cells separated by at least one photocontactor wall. Water from the aquarium is sprayed into each of the cells to create circuitous high velocity water flow and each cell and each photocontactor wall is illuminated by a high intensity light source to promote diatom algae growth within the growth chamber and thereby prevent undesirable algae growth elsewhere in the aquarium.
