I have a 1.25 gallon cloning bucket with 15 sites, its called the dewey mister. After a few days I get a build up of gunk or brown stuff on the lowest 1 inch of the cuttings. I have been wiping it away with a Q tip... Someone on here said to put 1 drop of clorox bleach in the 1.25 gallon rez daily, is the drop of bleach ok ???