ok best to show by example - check it out :
Baby Yotelings - hatched in a warm moist place on 50% sifted sand 50% sifted potting soil with a bit of mycorhizzal fungi added.
Now swims heard of a lot of ppl that like to keep their peyotes as babies for a long time - swims not one of them - he recons they need to be hardened off preddy fast.
A tad too much light was given to them - they got hehe sunburned - hehe not really they just go red to absorb more of the blue side of the light spectrum
Once nicely accidentally tanned they were moved to under some cfl's
This chuffed em up quickly and brought back their nice green glow
From the same batch one was grapthed and suntanned
once again moved to a better spot with less intense light
very quickly he got his glow back
and then kicked into growth
its best to keep a few pots in 1 tray and water from below - under cfl for baby cacti
Hope that cleared things up - btw that grapth is moving at light speed now - kicked into growth as soon as it went under the cfl's