Q.A shamrock housed plant.
My plant has been growing very well. Now many leaves and lovely white flowers. Many of the leaves are spotted with white blotshes: 1 eighth -to 1 quarter inch.How can I remove these marfks?

This could be due to water spotting from overhead watering, or pests and disease.
You may need to inspect more closely. Mealybugs can appear white as well as Powdery Mildew.
These links have more information.
https://www.gardeningknowhow.com/plant-problems/pests/insects/mealybugs-control.htm
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm