Axolotl Hatchlings Dead?

They've been in the hatching tank for about a week now.

Some of the eggs were white and some were black.
(Leucistic Parents, though, expected just black eggs?)

Some have started to form into the 'curved shape' that they begin to take before you see the forming of the gill's or whatever, but they haven't really progressed further.

It's been between 8-10 day's since I seperated the eggs into a near enough perfect tank set-up especially for them;
18 Degree's.
18x10x10 in size.
Air Bubbler/Filter.
Sand Substrate
And on the live & plastic plants they were spawned on.

Changed about 20% of the water after 4 & 7 days too.

Mine took ages too, they hatched eventually If they are dead then the egg inside the jelly turns a very notable cloudy grey.

These are the ones I currently have, you can see two grey eggs in there, if they aren't that colour then I doubt they are dead, if you aren't sure though then post a pic or two and someone will be able to tell you

http://www.caudata.org/forum/members/star-albums-my-axies-picture15324-mojos-eggs-arrival.html

I have a wide variety of development in my eggs at the moment. 2 have hatched this weekend (though they spent most of their development in the adult axies' tank), 3 that are looking ready to hatch any moment (again, from the adults' tank), then most of the rest were looking ready, but after comparing with the 1s I've just mentioned, they are a lot slimmer still, so expecting more development from them yet. Then, I have some that are the right sort of shape, but not as developed, some still kidney bean shaped + some that have only just turned into a tulip shape. Yet, all these are still developing!
Compare that with the eggs I gave to another member on here (not just Star) + all the 13 she had from me have already hatched - a lot of variety, all from the same spawning. Okay, so if Raziela's have been in a warmer temperature, they would've hatched quicker, but there is a lot of variety in mine, even thought they've all been kept the same (apart from the 5 from the adults' tank), since I seperated them into a seperate container the day they were laid.
So, don't panic yet - see how they go over the next week or so + watch for cloudiness, as Star says. It's hard to describe, but very obvious when it does happen.

If they are dead, they will very soon become milky or fuzzy looking. It may just be that they are in a period during development where you don't see much change on the outside.