I noticed this white coloured stuff on the top layer of my pon, is it mold?

It’s a self watering pot with wicking string into a reservoir, the plant is a baby pilea

Any help appreciated!

i switched this begonia to semi hydro because the leaves were drying, and she dropped most of the leaves she had left 😭

does anyone have any experience with begonias in semi hydro? i’m afraid she’s on her way out

I moved my hypoestes plant from soil to leca 2 weeks ago and it was doing really well until today. some of the leaves are floppy and starting to curl. Should I put it back into soil or wait it out?