Wet leaf can someone please advise.

Hi folks total newbie here to growing. I am growing some plants indoors, they are looking all healthy and growing well, but yesterday on one plant half a leaf appeared shiny and wet, I thought I hadnt spilled anything on it, wiped it off and left it at that, again this afternoon it had appeared again only half a leaf any ideas what this might be, plants are starting to bud.Am worried something might be wrong.

It's completely normal and nothing at all to worry about. It's the human equivalent to sweating when the plant takes in more water than it needed (so it's even more common in hydro) or the humidity is a bit high at the time. If the humidity is around 70% or more, then the plant just gave you a signal that you need to give it a draft or use a dehumidifier. If it's normal, then you're plant's just sweating normally.

Hi there many thanks for your reply sorry if I sounded a bit thick but am learning all the time , thank you

is it crowded in your grow space?

i tend to see this when there are two leaves on top of each other, as one breathes out moisture it is stopped from fully evaporating because of the leaf on top. this can lead to mould growths if left unchecked.

maybe do some thinning out if it is overcrowded and get a good fan in there circulating air, now that you are in flower you want to keep moisture above the root zone to a minimum.

devon and yorkshire are a fair way apart, i still like the username though

Exactly! Your plant is just transpiring or releasing moisture and working hard. I noticed they do this more when it's hot or leaves are stacked.