How clean is too clean for a fry tank?

Interesting.

Thinking about it a little more I'm wondering if lighting costs are an
issue. I'm wondering if there is fear of greater possibility of
bacterial growth that can cause deformities. Indeed potential
Hydrogen sulfide gas exposure would be an unnecessary risk. 2 good
sponge filters per tank and lots of water changes are starting to seem
like enough. Although I don't really see any great need for a
hobbyist like myself to growing out fry necessarily in plantless or
algaeless tanks.

Nutritionally, I was thinking simply about the color enhancing aspects
of some algae. The fry in the algae tank did not grow much faster.
But without such algae you would be introducing other color enhancing
foods at a later stage of development. I don't know if that matters.