Has anyone ever experienced a problem in their humidifier tank?  I have a ligt red residue that is in the bottom of the container on the staineless steel portion of the plastic tank. I only use distilled water in this.  The top portion does not come off for a full cleaing and the hole is so mall that you cannot get a brush in.  I have been unable to take a small amount out with the end of a q-tip.  i clean the container with vinegar and water routinely.  I have also tried a mild detergent in there.  Any suggestions?  I'm stumped where it is coming from.  I really want to get it out so that I don't breathe in any of it,  Help! JRThinner

I have never had that issue.  Sounds like you might have mold in the tank. You might want to try Control III Disinfectant CPAP Cleaning Solution. I have used this regularly and it works great.  It is the same stuff that the sleep labs and hospitals use to disinfect CPAP stuff. 

i had that happen to mine, and i too thought the top did not come off the tank - but when i actually sat and looked at the book there was a small little latch on the tank that pops the lid off. i was sure there had to be a way since it was important to keep it clean - voila there it was. good luck with that.