I don't foliar feed anymore unless trying to overcome some problems of some kind. I think the ferts drying on the leaves block some of the breathing and light receiving properties. Just spay some fert solution on a white board or glass and let it dry, you'll see a nice dark film. Also you can lead to powdery mold problems if done too much. Plants like to transpire that's how they work. so let them feed the way the want and leave the foliar feeding to when their roots are in trouble and you need to make them happy til you fix the cause of root problems.