24- hours in dark before harvest really necessary?

No it's not necessary at all. This is just something someone came up with and a large group of growers decided it made them feel good. This happens a lot. Shocking roots with ice water is another one. The grand daddy of all of them is flushing. Completely useless, but enough people thought it was a good idea so it stuck.

It is not necessary, someone came up with it recently and all of a sudden half the growers decided, "oh ye, dats the way". But it doesn't.... really.... matter. You can harvest no problems, you will lose nothing. If you want to do the dark period stuff, just harvest it with the root zone attached, and the juices from the root zone will flow thru the plant, but some may argue that it will only increase the cbd levels within the flower, wich is why some growers would preffer it, because they are lightweight. But man, it really doesnt matter, you can test it out tho, take that one as it is and then later give the others the dark period, and then think to yourself, wich one is the strongest... The root zone naturally holds a certain cbd(or derivative) percentage and by leaving the plant to dry while attached to the root you can only risk to bring that into the stem/flower, sure you could get some tasty juices too, who knows, after all every strain is different. But i sure as hell won't do it. Rather keep what's in the roots, in the roots, and not flowing thru the plant. Hope it helps and if you don't mind chosing answer it helps a lot in grower of the month competition. Thanks and good luck growmie.