Good afternoon all and hope you're well!

I'm a new bonsai keeper and have been looking after my Sageretia since a little before Christmas, all seems to be going well however I have noticed some white marks on the leaves as well as a very few leaves tips' turning brown. Looking into it i'm pretty certain i've over-watered.

However upon a few hours research all I can find is folks diagnosing white mould as almost a fluffy sort of material, this is not fluffy but flaky in comparison. I cannot see any white markings on the bark or the trunk so thankfully it hasn't spread there as far as I can tell.

Any advice would be much appreciated, thank you.

Looks like your water is very hard and has calcium carbonate in it. It drying and leaving a residue on your leafs when you wet them.

Thank you Nick for the quick and helpful response.

I'll look into a way around this if possible so thank you!