AI: Hydrogen Dioxide and Peroxyacetic Acid. ZeroTol 2.0 is an effective broad spectrum algaecide/bactericide that increases plant health by killing algae, bacteria, fungi and their spores on contact. ZeroTol 2.0 is labeled for use in greenhouses and nurseries and on professional turfs and landscapes. ZeroTol 2.0 controls foliar and root diseases and is safe to use on foliage and most open blooms. ZeroTol 2.0 leaves no harmful residue behind and has Zero REI. ZeroTol 2.0 can be applied as a foliar spray or drench.