Mine do that sometimes too, but from my experience I would just stop feeding it for a few rounds. Do you PH your water? Mine sometimes look like that when my lights are off, or just turned back on. It can be a lot of factors. Honestly though it looks really good and healthy. I also spray my plants with plain PhD water when I feed or water. I don't know if there is any science, but my thought is that the plant would know when its raining, And would prepare better to take in nutrients, just a hypothesis. Peace, and take care