My thoughts exactly on a cup of water. If you’re measuring the water input by cups, you’re severely hurting the plant by keeping it dry. I would soak that plant until it has complete runoff, and the root ball is saturated…then let it dry normally and then feed it regularly… I grow indoors, and most of my plants are in 3 gallon containers. They require a full feeding roughly every four days. They get fed until there’s runoff in the bottom of the saucer… your plant will reabsorb a small amount of runoff, but be sure not to flood the plant