About fertilizing houseplants.....?

First of all there are 32 ounces to a quart, 128 oz to a gallon, 16 oz or 1 pint is a half quart As for fertilizing your peace lilly. You can use a pinch of miracle grow as it is water soluble or the fertilizer for aquatic plants. Just read the directions and don't add any more than it tells you to do. After a week or so you can change the water in the beta vase add another small pinch and let it go. If a plant is going dormant or placed in a lower light condition then cut down on the fertilizer.