r/PrayerPlant

I got this plant about 6 months ago, before I knew much about them. I was using tap water and at first, everything was fine, she was pushing out leaves like it was her job. However, I started noticing these little speckles on the leaves and eventually they would turn crispy. I did a thorough check for pests and found nothing each time. For probably 2 months I watered with purified water, then for the last month I have watered with only distilled. But the lower leaves continue to get these speckles. Is this a watering issue? Does it take time for the tap water minerals to completely leave the plant?

I have a prayer plant I got in June and it now isn’t standing up at night and has brown leaves as well. Any care advice would be very appreciated