I'm one of those who leaves the lighjt on 24/7 due to fry have poor eye sight and mainly have to bump into food so you do want to have alot of rotifers in the tank. As far as being worried about fry sleeping they rest when they want to. My first 2 batches just slept on the heater at night. They were so cute. You got to do what works for you! Some poeple cover the outside of the tank to keep it dark with light only from the top so the fry will not try to eat their reflection, some put white paper on the bottom of the tanks so the fry can see better, some do all dark.
I don't cover the fry tank after hatching. I did put a white paper under tank #4 to see if it did anything, only thing is so far is that I can see them better when they are over it.

I like to try new things to see what works some do, some don't. Maybe you can learn from some of my errors

I tried to post them. I have some fry that are 4 half monthes old I still keep the light on for them because this is my grow out tank and I have other younger ones with them.
Selco I've read good things about it. It is alittle $$ so I don't use it. I tried once to feed my brine shrimp rotifer diet and the smell was bad the next day, haven't tried to enrich them again. The rotifer diet has isochrysis-DHA and tetraslmis-high lipids and amino acids. Pavlova -high DHA profile excellent for enriching rotifers and brine shrimp and EPA is high. I don't use it.
I keep my fry water green with rotifer diet to keep the rotifers enriched anytime the fry want to eat. I have read of them eating too much when you add brine shrimp because they are bigger than the rotifers and dying but I have never seen this in my fry.
I keep my fry water packed with rotifers (co-culture) so I don't have to add any everyday.
Good luck! Let us know how things go good and bad so we can learn from each others errors.
