I am about to take the plunge and send off an ICP test. Will be interesting one way or another. Good idea about a daily/nightly purge. Will get onto it this afternoon.nope, would not make that correlation at all. do an icp test to see where you are at. I've recently add an hourly "purge mode" to my tank where all the pumps ramp up to 100 percent for a minute.....that might be helping to stir the tank up.....not sure if thats related but its the only thing i can think of as different. I used to eat thru a roll a month.