When to water orchids in Leca medium

[Rocshpy]

Hello all :-) so i just repotted 4 phanelopsis,1 dendro and 2 oncidium in leca medium in a plastic pot with lots of holes on the side. They were previously in bark but i had problems with white fungus and springtails even tho i watered them once a week. Thing is i am not used to this media and i don't know when to water them, especially the oncid and dendro...i watered yesterday and today it seems dry already... I am starting to question if i did the right choice or how long to wait for improvements/signs of not going well...What problems did you guys have when switching to completly different media or how did you handle it? I'm feeling very frustrated and sad at the same time, actually thinking of giving up even tho i love them and dont wanna lose them. Thank you!