Good luck!
My assumption is that rotifers will likely be too small to be adequate food for long, so I would try to start something else as well - baby brine shrimp are probably the simplest and fastest option, though live copepods may be a more nutritious option for future attempts.
Lysmata shrimp seem to always spawn around lights out (9:30-10:30pm in my tank), and they try to climb up to a high spot and then let the larvae go. They will basically always molt later that night, and I believe fertilization of the eggs happens during the molting process, so if you're looking for a constant supply of larvae, it may be better to leave the shrimp in the main tank. My approach is to turn off the pumps for that hour or so, black out the room as much as possible, and then have a light source somewhere, and the larvae will all crowd towards it (plus most larvae of anything else that spawns), and you can collect them in an air powered collector, with a fine sieve (maybe 200-750 micron), or even a turkey baster.
As said, they don't really eat phytoplankton, but there's some evidence in papers for there to be better feeding response with some present (won't make a difference in whether anything survives from the batch, but probably increases survival percentage in a successfully raised batch), and getting an appropriate amount of flow could potentially be tricky. It seems they do well with lower flow situations, but you want to especially avoid flow that pushes them into a wall or corner, as they are not strong swimmers.
It's also critically important to manage light into your vessel. The larvae are attracted even to dim lights, and multiple light sources will confuse them and cause them to run into walls or other things (and very bright light causes them to spin in spirals), so I think an ideal setup in a glass tank is actually just to black out the sides (using something removable if you want to look in sometimes), and then having at least a dim always-on light overtop. During brighter lighting during the day they will be less confused by room lights and things from the side, but at night it is important to really only offer one light source, since it is their primary mode of navigation/orientation.
There are tons of larval stages (something like one a molt), so you should start to see some differentiation in shape 3-4 days in, and then every couple days beyond that. Some of the stages are more subtle, but there are papers showing differences in zoea and under moderate magnification it should be apparent.
