Do they hatch all at once or are they spaced out over days? In other words, if my 3 pregnant females are still very obviously carrying eggs, then is it safe to do a small gravel vac without worrying about babies (I don't currently have a clean pair of pantyhose to put over the vac) - or is it possible that there could be some that hatched already?
I don't know how long these gals have been carrying the eggs - they were shipped to me already pregnant last week.
In my experience they usually hatch very close together. Make a big disturbance with your vac and it will shoo most of the babies away. You can then let the water you sucked out settle and check for babies. I haven't lost any in a long time like that.
So even newly hatched I will be able to see them swimming around? Will they be red or clear? I keep seeing little specks of red stuff but I'm pretty sure it's just poop
You should be able to see them even though they are no longer than 2 mm they look like miniature shrimp Mine have been white just after they have hatched and some even pink Keep looking for them and keep a magnifying glass near by!
Mine have been white just after they have hatched and some even pink 
Keep looking for them and keep a magnifying glass near by!