elgecko
I've got a magic window!
What I've read on the internet and the instructions I was given does not say anything about running an airstone.didnt notice any air bubbles used to incubate the eggs. what you should have done was place the eggs in a test tube filled with dH2O with an airstone. once when the eggs hatch, you can put them into the larger tank.
My hatching tank is a small, less then 1/2 gallon tank.
I'm using distilled water. I have thought about trying rainwater that I collect for my plants...Years ago i collected some from the wild. needed specimens for my natural history prof. They apparently are on all of the major Hawaiian Islands. I kept a few in the lab they grew up and died. Later i dried up the tank for a few months and then added water. The eggs laid by the few that i started with hatched out. These guys might have some interesting dormancy mechanisms, based on the locations that they are seen in Hawaii. Years of dormancy isn't unusual. Might need some things to break dormancy. Similar things are seen with daphnia/moina eggs. Some need cold (daphnia) and others seem to need long dry periods (Moina). Might not be too odd. Also, RO/distilled water or rain water might be doing things to help the eggs hatch. Might be related to osmotic pressure.
I'm waiting for the next huge winter storm on the south west side of Maui to go look at the most logical place for them. With 7-10 years of drought, makes one wonder how they survive long dry periods.....
MTF
Like you and swords mention, maybe a cold period is needed to get them to hatch.