Hello, I just started growing in dwc. Can anyone h...

You have a nutrient problem. It looks like a deficiency but its probably lock out. Check for root rot. Smell the roots, they should smell like nothing or clean fresh dirt. If it's got a funky smell that's root rot, roots will turn brown Check your pH, 5.5-6.5 do not go out of it. Check your ppm, as the water gets drank your ppm may rise climbing to high and you'll get lockout, you'll need a res change. Check your temperature. Anything of 85F on the roots will make rot and the plant cannot breath oxygen from the water at that temperature because it doesn't hold enough. Make sure your water level is BELOW your net pot. By at least an inch or 2