So far on APD, searching "siesta" seems best, but only a few comments, questions, few answers. George Booth saying it didn't hurt the algae but he lost a good plant. Tom Barr saying, essentially, that it is much wiser to attack the problem of why you have algae in the first place, get the balance right and you won't have the problem. One person saying it helped with the algae but certain plants were unhappy. It was apparently promoted by Denerle at some point long ago. You'd think if it worked, we'd have heard about it.
that's all the time I'm going to devote to the search.