I have spawned the Black Phantom. It was about 12 years ago. I didnt have an RO unit back then, so I was able to do it with my house water supply which is quite hard and alkaline.
Apparently, all tetras eggs are somewhat sensitive to light, but the only fish eggs that I have put in total darkness have been for neon tetra. Other fish eggs I just shade from direct bright light.
I have yet to try any hatchets, but I do plan on trying the marble hatchet at some point.
I will try to offer you any advice I can. I guess that is the best use of a forum of this name.
I have no experience with the fruit flys though I understand they are quite good. I have had a lot of luck conditioning my fish with a beefheart mixture, BBS, and a good quality flake. In the past I have collected live pond food, and I intend to do that again soon, though this year is looking so dry, finding ponds may be difficult.
I just may culture some mosquito larvae in by back yard this summer much to the dismay of my nieghbors.
Thanks for your welcome.
Virgil