Buckets, Collanders, & Calcium Chloride
I also use a 5-6 quart bucket with a collander on top. I put about 1-1.5# of calcium chloride pellets into the collander. Last spring I emptied over 5 quarts of water out of 7 buckets.The calcium chloride is available in 50 or 80# bags at any garden supply store. The buckets and collanders can be had for a buck apiece at most dollar stores.I do make sure that my bilge is pumped dry so that I don't have a built-in source of moisture after closing. About mid-winter I may add another 1/2# of calcium chloride to the collanders.I used this method last year for the first time and had good results. A friend that told me about this technique has been using it for years with no mildew.Rich