Sorry mate no exp with onyx, or i'd have chimed in.
Mossy our days with snow white are numberd. When i get the cam back tomorrow night i will get some pics up for you to see. It's not dead, but it doesn't like light at all. I woke up to it on christmass day. But i didn't want anyone fretting over it on a family day. So was going to break the news later. At least it's not like damping off, not like wilted at the soil. But the first set of leaves are crispy now. The cotlydons are still ok, and there is new growth still "comming".
Oh well, it was something while it was here
Still the first albino AF, even it it didn't make it far. If it had some kind of green it would have been better, but that pale.. dunno. Maybe it'll make it.. I have it a mile from the light right now.
Once you see how healthy the rest are it's hard to figure out WTF.. It has to be the light.. There is nothing else that isn't spot on. Like you said there is no book on some thing like this.