phil-t wrote:
So, after all this - is there something I can use in the grey/black tanks that will take some amount of water/dilution and not freeze? I'm thinking, leving northern NY in 0-20 deg. weather and heading south. Just beable to use the bathroom for washing, etc. till we get a day to the south.
BTW - I winterize by draining everything and adding pink stuff to the system.
Rock salt is one viable option for black and gray water tanks. It's probably not great for septic systems (in large quantities), but it will do fine to keep things from freezing down to reasonably low temperatures and will (with sufficient water) all dissolve and not cause clogging, will not attack plastic pipes, etc.