Mine also was doing exactly as yours with me doing the same things minus the Miracle Grow. I have never fertilized her other than the occasional used tea bag. She is doing famously this summer, however, and the only change I made was to pull the shade more. She sits in a west facing window and I keep the shade pulled from about 9am to 6pm. It is an off white blind that allows light through but no direct rays. I water with well water (12-14 cups per watering as she is a large variety) about every four days in the summer and once a week in the winter; just as the soil feels dry. We also mist her occasionally between watering which she seems to respond very well to and I am a Nazi about keeping any damaged, old or dying leaves cut off, trimming them at the soil line. Another tip for brown tipped leaves is to simply trim the leave tip off, always trimming to it’s natural shape. I have done this numerous times with great success. Our peace lily is very precious to us and we have enjoyed watching her thrive. We call her ‘Evelyn’ which means ‘living cascade’ as she is a Domino variety with various sized leaves cascading down. I wish you success!
Mine also was doing exactly as yours with me doing the same things minus the Miracle Grow. I have never fertilized her other than the occasional used tea bag. She is doing famously this summer, however, and the only change I made was to pull the shade more. She sits in a west facing window and I keep the shade pulled from about 9am to 6pm. It is an off white blind that allows light through but no direct rays. I water with well water (12-14 cups per watering as she is a large variety) about every four days in the summer and once a week in the winter; just as the soil feels dry. We also mist her occasionally between watering which she seems to respond very well to and I am a Nazi about keeping any damaged, old or dying leaves cut off, trimming them at the soil line. Another tip for brown tipped leaves is to simply trim the leave tip off, always trimming to it’s natural shape. I have done this numerous times with great success. Our peace lily is very precious to us and we have enjoyed watching her thrive. We call her ‘Evelyn’ which means ‘living cascade’ as she is a Domino variety with various sized leaves cascading down. I wish you success!