I experienced a bit of light burn. I invested in a PAR meter(I bought the Photone app extension for full spectrum LED). This will not only allow me to properly set the height to prevent burn, but save some money by allowing me to dim the lights. Each stage of growth has a maximum amount of light appropriate to grow conditions (stage of plant life, desired growth, and addition of CO2) Growing multiple plants in one pot allowed me to compare and contrast some plants thrived others didn’t suffer (too much). Beginning of the week (2nd day of the week is reservoir change). This week we did the change on the third day. One reason I was adverse to the organic root plugs was organic material is a breeding ground for unwanted and wanted bacteria and fungus. I had trouble with algae; I chalk this up to ignorance. Light and standing water allow algae to grow (which I knew and didn’t apply). The plugs were just above the water line (still constantly saturated) and exposed to light. I eventually covered the plugs with more clay pebbles to block the light and starve algae. This caused a dirty a** reservoir and promoted unhealthy root growth. I already had hydrogaurd on standby. Lastly, I moved some of the kids to their own tent and reservoir. I paired the best grower (best root growth) with 3 other struggling plants. As for the other 4, I split the next best 2 and worst best 2. Then paired them as such.
I have small yellow spots on leaves. I want to say it starts at tips and travels down. I moved light away and it seemingly gotten better. I moved tents for bigger space and it might have returned.
Your nutrients are to high. Cut them in half. Hydro gives the roots direct access to nutrients so at full dose the plant will start getting nutrient burn.
Also you don't want light to get into your buckets, Any light leaks will lead to root rot. Raise the pebbles above the holes.
check out this diary for how much nutrients should be used in veg.
growdiaries.com/diaries/86068-barney-039-s-farm-utopia-haze-grow-journal-by-chow-13/week/445013
Happy Growing