Simple question related to this topic...
Do I need to 'cycle' black fluorite prior to planting, or can I begin planting after rinsing and having the substrate in the tank?
You can plant right away, no problem. Cycling is to prep for the fish, shrimp, or any other fauna you intend on adding to the tank....that are all sensitive to the nitrogen cycle status.
As for rinsing flourite...I only rinse lightly once or twice. There is no point in vigoursly washing it over and over since the substrate is so fine as it is that it will cloud your water no matter what on the first addition of water. I have used flourite the most out of all substrates (btw it's the best out there IMO) and it always clouds the water initially after the first add no matter how much I rinse it.