Good evening
I was hoping someone could give me some advice on my bonsai.
I recently purchased two weeks ago this tree and it has developed white mould like substance on the top layer of soil.
I have tried to scrape off and it re appears. Usually more visual when it the soil is drier and ready for watering.
Overall the leaves seem healthy and it shows good signs of new growth each day.
Any help would be appreciated
Thanks!

Over watering. Poor air circulation in and out the soil.

Thanks,
Do you have any suggestions how I could help my plant?

This is limescale. It means you are watering with hard water. Nothing to worry about at this scale.

Finnbonsai wrote:

Thanks,
Do you have any suggestions how I could help my plant?

Repot in proper soil and pot. Water when soil is dry, not on schedule. Place plant where is good air circulation and good sun. Outdoor will be best.

Thanks, I know the water in my area is Hard water compared to other towns. If I use a vinegar solution and then switch to rain water would this be okay?

As said, it is not an issue. Just repot as usual every 1-3 years and replace the old soil and it will be ok.