HydroBlu Ultrafiltration Hollow Fiber ReplacementWater clarity doesnt always indicate clean water as bacterias are an unseen contaminate with incredible destructive power. Our Standard Hollow Fiber ultra filtration membrane filter is built to remove 99. 999% of bacteria. Through size exclusion hollow fiber surpasses EPA standards and will last up to 10,000 gallons. Dozens of tubes have microscopic holes (0. 1 microns), which allows clean water to pass through, but creates a barrier to damaging