Product review (5 stars): Wonderful
My humidifier did not mention using a solution like this one to prevent algae.  I cautiously added a scant capfull to my unit's 2 gallon water tank with each refilling thinking it was unlikely to cause problems.  I am Thrilled at the difference it has made in algae growth and recommend it to anyone who runs a humidifier frequently. We use RO filtered water in our Honeywell humidifier.  Our house is on a well so we have do not have chlorine in our water and we do have very high mineral content. I think this product has cut my need to clean the unit by half and recommend you try it.