Seedling care tips

[Luizacft]

Hi, all! Thank you for responding.
1 - I actually live in the south of Brazil - it has cooler temperatures than in other states.
2 - Those pots have holes only in the bottom.
3 - They are in a part of my balcony which they receive no direct sun.
4 - I think I'll use a 1/4 strength foliar fertilizer every week. What do you think of this regime of fertilization for seedlings? Is it too much?
New question: The seedlings are planted in tiny rocks. Would you change the pot mix to bark+sphagnum at this point? Spring will start soon in Brazil and winter is already gone at this point of the year.

I'm really new to this seedling care. Sorry for too many questions. :-)

Thanks in advance!