Nigel -

That Wiki comment: ... may be due to the odor of algae produced by early units looks like it was written by some young pup who never actually used one - that worked right. I wonder if it might have been a bit tongue-in-cheek.

The tradition, at least in my areas where they were used, was that the humidity produced by one made it "like going into a swamp" where everything sort of dripped and oozed. Mildew or moss growth was more of a problem where this method works best. If you're getting algae the outside humidity is probably too high for one to work very well.

It is true that they sometimes developed an odor, but changing out the excelsior fixed that pretty easily, and there generally was very little odor since the fungus doesn't grow when it's "really wet" (i.e. when it's running constantly) and in many climates it dried out so fast that there wasn't enough moisture to grow fuzzy stuff when it wasn't being used. The odor problem appeared most often when people tried to use one "intermittently" and kept the thing consistently "about half wet."

In the areas where they worked best, you turned them on around mid June and turned them off (and drained them immediately) early in September. No stops in between, for more than a few hours at a time.

Some local water supplies do "just naturally stink" and evaporation concentrates whatever "other stuff" is in there, and poor distribution of the "drip" through the media could produce some algae; so the odor was a known possibility, but never much of a problem in units I've seen in use.

(Or maybe it was just that grandpa smelled so bad we never noticed the cooler odor. (?))

John