New Strain Starting - Canna So Hard by the Seed Kompany

I started these in a glass of water, and they only took 2 days to sprout.

I've moved them into rock wool with pretty much pure PHd water (5.7).

Any tips on keeping them healthy as seedlings? This is my first time starting from seed in rock wool.

I'm really hoping for a female :)

More about the seeds

Cheers!