Floating in the Shower?

We learned something new today about the RV life.
Make sure that you trust the electronic gage that tells you how full the holding tank is and empty the holding tank for grey water when it says it's full.
As we started to do the dishes this morning I went into the bath area and opened the shower door to find the towels and laundry bag floating in the shower base.
This meant that the holding tanked had filled to capacity and just a bit beyond.
Thankfully I went and opened the door to put something in the laundry bag that we keep in there. Why I did that I can't really tell you but I am sure glad I did.
In the next few moments we would have been doing the dishes and rinsing them off and it would have surely over flowed out of the shower and onto the floor.
No Shit!
Thank goodness!
Just Grey Water!