I bought my zero pitcher about 5-6 years ago and I can’t say enough about the entire process. The filters don’t, do not, need to have water run through it, when you put a new one in.  I have always hated drinking water since a child, as I never liked the taste of it.  I have absolutely no problem drinking the water that comes from this.  I take on vacation my pitcher and a extra filter, then we know what we are drinking. Great deal and love them.