It’s the night of 5/31 going into 6/1/2014, and right before 2:00 AM (6/1) I pulled the tile for the sanitizing H2O2 (Hydrogen Peroxide) dip. While going through the 15 minute treatment at 4 ML per 0.5 gallons of broodstock water, I wiped out the BRT which was used for Spawn #32 and refilled it with 10 gallons of water from the broodstock tank.  When I went to check on the eggs, with 25 seconds left, I discovered that about 30 larvae had already hatched.
I moved the tile into the BRT with good air flow using a coarse air stone and turned out the lights.  I then spent a little time pipetting some of the larvae from the specimen cup, but I ultimately did not get them all and some had to go down the drain.  I had to wonder – would these larvae be viable long term, or would their exposure to H2O2 burn them up and render them useless.  So I wasn’t overly concerned, and I also didn’t want to add too much of that bath water into the BRT.
I’ll try to check on the hatch again in the next 30-45 minutes…I wonder if they’re going to go really fast, or if it’s in spurts (you may recall my concern over “morning” hatches…)
UPDATE – as of 4:20 AM, a last check of the night after just under 2 hours reveals no further large hatching occurred.  I wonder if they’ll hatch come daylight?  Hard to say…