Having multiple issues here… My alocasia has spider mites, but I only see it in the soil. The leaves look good still. Should I repot it? My ficus elastica has a black spot on only the one bottom leaf; what could this be? It is next to a humidifier and other plants. My silver nerve has constant mold growing on top. I keep scraping it off, but it seems to grow back faster. Should I also repot this?