Hello, my mother gifted me a Hawaiian umbrella bonsai for Christmas it has done well until this past week it started showing a white mold type looking layer on the soil, I tried scraping it off but turns out it's all throughout the soil. I'm thinking it might be mineral related since it kinda looks like salt the deeper I dug. I also came to find out that it is wired into the pot so I dug out what soil I could and replaced it with miracle grow garden soil. I also cleaned the rocks in rock tray with vinegar. I also want to note that I saw bats coming up from rocks underneath when I cleaned them. Thank you for reading and thank you in advance for any advice. I really want this tree to last.