I was gifted a beautiful philodendron gloriosum for Christmas which I would call mid-sized at the time. It was in good health and purchased from a reputable rare plant dealer. Since then it has grown quite a bit and I’ve been watering and misting it regularly (more or less as often as planta suggests for my plant). Over the last few weeks I’ve had new leaves sprouting pretty quickly. They are much larger than the leaves present before them and the top one is much taller. They appear to be healthy. My concern is with the older leaves that are smaller and further towards the base of the plant. As the newer, larger leaves have grown, they started slowly turning lighter green and eventually yellow. I’m wondering whether this is normal? Ive read that this can happen as new leaves grow because the plant is using more of its energy on producing the new leaves. I’m in Michigan and the natural light has been less than ideal seeing as that it’s winter. I’m considering giving it some artificial light but I’m wondering whether I can prevent this? I’m scheduled to refertilize her in a month or two and as far as I can tell there are no signs of pests. Please feel free to let me know if this is anything I should be concerned about. Thank you all in advance.