Phosphorus (P) is the limiting nutrient controlling productivity in most inland freshwater systems. Several materials have been proposed for use to remove excess P from wastewater treatment, including volcanic lapilli and ash (tephra). There is limited data in using tephra as a P filter. There were two objectives of this study: (1) to determine the physical feasibility of tephra as a filter making sure the infiltration rate remains high enough to use under prolonged saturation, and (2) to test the suitability of volcanic tephra as a medium for removing P from an artificial solution on two different volcanic tephra materials: Okato and Papakai tephra. The experiment used a synthetic P influent solution (20.5 mg P/L) and a solution residence time in the columns of approximately 3 hours. By the end of the experiment infiltration in both tephras was adequate for use in wastewater treatment systems. The Okato tephra absorbed nearly 8 mg P/g tephra with 97% of the total amount of P added to the column over a 54 day period. The Papakai tephra absorbed only 4 mg P/g with a 52% of the total P added to the column. (Contains 1 table and 3 figures.)