Help! Potting cacti grown from seeds

[Steve Luoma]

Hello,

I have recently begun growing a batch of cactus plants from seeds in a
"Cactus Egg" purchased in Arizona.  The instructions said to pot the plants
after they reach 1 cm.  The seeds are for Saguaro, Barrel Cactus, and
Prickly Pear.

I purchased Schultz Cactus Soil and Cactus Plus liquid plant food in
preparation for the transplantation.  When potting the seedlings, how much
space should I give them?  Also, should I water/feed them right away, or
wait a week as the soil instructions recommends for mature plants?

Thanks for your help.
Steve