Don't use foliar sprays. it's rarely beneficial to the plant and more often a potential cause of a problem if you do it without cause.
It's just a money-sink product. If leaves have a problem and there is a solution that involves spraying them, that's the time to do such a thing.
Keep it simple. You'll save a ton of effort and concern. More products used or dumped into substrat is not better and often times is a bad thing waiting to happen.