is there a time shrimp eggs typically hatch?

Hi,
I have asked this about fish before... wondering if there is a pattern to when I should watch for the larvae of peppermints, skunk cleaners and fire shrimp? I have an unknown quantity of peppermints (don't see em much) and 2 pair each of the cleaners. They are often holding eggs. Don't want to leave the pumps and refugium lights off and sit waiting at the wrong time, my ph meter not to mention patience starts nagging me. Have a larval snagger but in a couple tanks the flow is probably too high for the larvae to get in.
 
My friend caught her fish eating a batch of peppermints a few years ago and gave me some, raised them to settlement. Would like to catch any shrimp I can. The peppermints had the same problem I have read about in other shrimp, at a certain age they start ripping pieces off eachother when they pass too close and after settlement they are downright vicious. So am pretty much planning on culling them down to a few in hopes low stocking will make a difference as they age, experiment with rearing containers, have a nutritious food for the pipefish, and experiment with my silly kreisel design.
 
Also curious if anyone breeds Pedersen's Anemone Shrimp.
Thanks,
Kate

I've found that my Peppermints and also my Cleaners tend to hatch within an hour or so after "lights out".  The nights I expect a hatch, I turn the pumps off right after lights out, set up the snagger, and check every 15 minutes or so.  Keep the room nice and dark.  If after an hour and 15 minutes or 1 1/2 hours nothing happened, turn the pumps back on.  I usually find things happening (if they are going to happen) at around 45 minutes to 1 hour.

My Peppermints don't hatch until middle of their dark cycle.

Don't let fear and common sense stop you! =]

What Jim says has been my experience, too. Lights out, then the parent shrimp is all over the tank releasing young.

--Andy, the bucket man.
"Not to know the mandolin is to argue oneself unknown...." --Clara Lanza, 1886

That`s what everyone says...mine are just a pain in the butt. 

Don't let fear and common sense stop you! =]

I have seen the same as Jim. Though I will add that if there is any interruption during this time, they don't hatch until mich later in the night.
If I am collecting other larvae and the peppermints haven't spawned yet, they delay and hatch in the middle of the night and I loose them.

figured it was something like that.  Thanks guys! I will turn the pumps off earlier and leave them alone for a bit.