Suddenly the coffee coming out of my big Keurig was scarcely colored.  I tried to brew again several times with the same result.  So I bought some bottles of the descaling solution.  
When it arrived, I followed the procedure and then tried to brew some coffee--no change! I used a second bottle to repeat the process but whatever the problem with my machine is, this did not fix it.  No clue what is going on, but this thing is taking up valuable real estate on my counter and I am about to get rid of it.  The descaling solution probably works fine in ordinary cases, but it didn't for me.