We have been in our new house about a year and have noticed COPIOUS amounts of orange slimey snot adhearing itself to the inside of the toilet tanks. We are on a well with a water softner. If we did not have the water softner the water would be orange due to the high iron content. Is this slime a byproduct of the softened water? My wife and I are careful not to flush the toilet or open any other valves during a water softner regeneration, and this slime is not present anywhere but inside the toilet tanks.

 

It sounds like some type of bacteria growing in the tanks. Since toilets really don't get used as much as other fixtures, water is not changed out as often, giving time for it to grow. You may want to try turning off the toilet water supply and flushing to get the water out of the tank. Then you could use an anti-bacterial cleaner such as Lysol or even a bleach/water mixture to thouroughly clean the tank walls and bottom. If you use bleach, be careful not to get too much on rubber parts in the tank as these wil deteriorate the rubber. Rinse well and refill the toilet. Check often and see if this helps. You should not have to worry about using water when the softener is regenerating. Good luck.