I have a tank with neon tetra disease running rampant.so after I have culled the tetras in there how long of a fallow period before the tank is safe again? I have MTS, bladder snails and pygmy corys that appear totally unaffected in the tank as well so can they host it as well? My plan at this stage is to restock with p. Signifer so are they susceptible to ntd? Because I've got fish in the tank already id really prefer to wait it out than break it all down and bleach everything and start again.