I am reading conflicting information regarding PO levels in the aquarium and the relations to algae. The conflicting information is that GSA appears because of low PO levels ( 0 - 1 ppm); however, another website states that PO does not cause algae because he has high PO levels ( 5 - 10 ppm ) without any algae bloom. Other websites states recommended PO levels to be between (0.5 - 1 ppm) and others state higher between (3 - 5 ppm). I am lost due to conflicting information in where the PO levels should be to get rid of GSA. Also, will high PO cause algae. Currently, the PO level is as stated: Tap Water = 0 - 0.25 ppm (hard to tell the difference). Aquarium = 2 ppm Thank you for any information!