Thats about right one fill should last around 2 mnths, 25 l bag should last about 6 mnths.
hi guys sorry to jump in im going wfp next week and di only.my water is 85 ppm im in wales.ive just got 1 13litre di vessel, should i get another 1?what size ?thanx
And remember only fill the di tanks up 3 quaters as the resin will expand to fill up the whole bottle, Luke