Q.Fishbone Prayer Plants Leaves Don’t Seem As Happy?
Hi, my Fishbone Prayer plant was producing leaves happily when I bought it, all uniform in shape with deep green fishbone markings. It went through a period of flowering with no new leaf growth and took a while to recover from that, now it is producing heaps of new leaves big and small, but I have noticed that these new leaves are much wider and a bit shorter than the older ones. They are also very faintly purple on the underside rather than deep purple, and the dark green fishbone markings are much fainter particularly near to the base of the leaf. I have moved it just after the flowering period to a spot with medium to bright indirect light, rather than bright indirect light with direct morning sun where I had it initially, as one of the leaves starting curling and I read up on it and decided it was getting too much light, but now I’m wondering if the way the new leaves look is due to it having less light. I’ve attached photos of the old leaves and the new leaves to show the difference. I don’t mind the appearance of the new leaves but I’m a little worried if it’s the symptom of some underlying issue.

Certified GKH Gardening Expert
It does appear to be lacking in light, slightly. The real issue may stem from overly moist soil, or pH issues. I would go ahead and treat with a fungicide to prevent any issues from worsening. This article will help you with fungicide use:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
Make sure to give the plant proper care to avoid future issues. These articles will help you to know what these plants prefer:
https://www.gardeningknowhow.com/houseplants/calathea-plants/calathea-zebra-houseplant.htm
https://www.gardeningknowhow.com/houseplants/calathea-plants/growing-a-pinstripe-houseplant.htm