Product review (2 stars): Not a 4 month supply...
These are NOT a 4 month supply, as each time I put one in the little cage, it almost instantly dissolves. If I put a new tablet in each time I used my humidifier, they would last 2 weeks.  However, they do work as advertised.  The water feels a lot smoother to the touch.  I think when we install our water softener in a couple of weeks, these will no longer be needed.