At what point would you move a Phal species seedling out of a 50mm pot

[OzPhal]

Originally Posted by CTB

When did you pot last? Once a year potting is usually enough and then sometimes it just needs fresh media not a bigger pot size. I wait till I can see roots, either climbing out or coming out of the bottom, then I go to a bigger pot. The smaller the pot the better. Less chance of overwatering and over fertilizing.

All of these seedlings I've only received this year - some were sent bare root and others were packed in sphagnum moss and are showing some signs of root rot... some I had to temporarily put in larger pots whilst waiting for my 50mm clear square pots to arrive... a few of them that I want to re-pot are actively showing signs of root/leaf growth which is great! others are more an emergency re-pot to get them out of sphagnum moss and in to my bark media so that they're not so wet...