I have 6 300 watt cobs on the plants. One per plant that is about 3 feet above the plant. I am using GH nutrients. PPM is 560 and pH is 5.9.You might get a little more help if you describe your grow. Light food water RH temp.
I have not done a foliar feed. This is a RDWC system so it all goes in the water.Have you done a foliar feed, spilled any nutes on them or sprayed them down and put back under the lights wet?