As far as I know, Flourite will not leach phosphates.
Do note that while unbalanced nutrient levels can cause algae, phosphates (alone) cannot. In fact, we actively dose phosphates into high light aquariums (amongst other fertilizers).
Do note that while unbalanced nutrient levels can cause algae, phosphates (alone) cannot. In fact, we actively dose phosphates into high light aquariums (amongst other fertilizers).