"Slushy" rv antifreeze

[rogeru]

We have had a very cold several weeks in Cincinnati. I went to check on our TT and found the rv-type antifreeze was nearly frozen in the toilet - very icy slush. Never had this before. Does anyone know about this condition? I have completely winterized the rv for the three years we've had it, and had not had any problems. But it's been unbelievably cold this winter for this area. Hoping the lines aren't frozen. Stuff is supposed to be good to -30 degrees