Spraying yoru plants with plain water can leach nutrients out of the leaves. Make sure you're actually WATERIN"G your plants with a correct fertilizer, but be very careful since you're running a heavily pre-fertilized soil on young plants, which in and of itself can be a source of problems. Also, with LEDs, you'll have to make extra sure that you are not overfertilizing or overwatering, as compared to a hotter, brighter, HID lamp.
I'd lose the spray unless you find you actually NEED to foliar feed for some reason, which I don't see.