Average mortality, malformation rate, and pericardial area of 96–h postfertilization zebrafish embryos (n = 3, 10 embryos in each vial) dosed with 5% porewater with different pretreatment methods: (a) control with high-performance liquid chromatography (HPLC)–grade water, (b) raw porewater, (c) filtered porewater using a 0.7-μm glass fiber filter, (d) porewater after ultracentrifugation at 287 472 × g, (e) porewater after slow-speed centrifugation at 1000 ×g, (f) porewater after flocculation with alum, (g) porewater from overnight resuspension of settled particles after flocculation by alum. Error bar represents standard error. *Significant difference with the HPLC-grade water control.