Just buy some swimming pool algaecide by the gallon to treat the humidifier, it's much cheaper than the bottle for humiddifiers and is the same thing only you get a lot more in the gallons for same money I bought a gllon before winter started this year and I still have some in it.

Since posting this. UPMC, Pittsburgh, Oct 2011 until Jan. I averaged about 2 to 3 surgeries a week there. w Can't have jaw made as bone is deteroriating steaily that is left in jaw. Mersa is to blame. Feeding tube . Had trach for 4mos. Got it out April.
--- Passed away 5/14/14, will be greatly missed by everyone here