Why discolouration in root and spots on leaves?

Hello, you actually have two different symptoms: the severely affected leaves are due to pH fluctuations, something very common in hydro, the pH perfect doesn’t help enough, you often need to add pH + / - to ensure stability. Otherwise, the less affected leaves, just with small rust spots, that’s the standard calcium deficiency, you always need to add cal mag, especially in hydro, add some and it will recover right away. I hope this helps you! 🚀

Looked like you have some rot going on. You can treat her with some peroxide for a day, change the water, and then incorporate a compost tea without using molasses. Brewing a proper batch of compost tea and adding it after every res change will help keep the good bacteria flourishing which will kill off the bad destroying your roots. Also, make sure you have good airflow, turn that reservoir into a cold jacuzzi for your roots. You may have to trim away some of the dead root material and as a last resort, you can transplant her into coco coir. Coco will retain a lot more oxygen in the root zone which also kills off the bad bacteria and you can use your hydro nutes. I personally have done this last step to save 2 dwc plants.

Do you have any nutrients in the water? What's the PH and EC of the nutrient solution (if there's any in there)? Also do you use tap-water or RO? The rusty spots look like calicum issues, but depending on the type of water/nutrients it can be due to a deficiency or a lockout. I have to say the roots really don't look well! Are they fully in the sun like this, or do you cover the bottle, so they're normally kept in the dark?

Hello.. Hope you are well.. She's looking lovely.. Do u have a air pump oxygenating ur root zone.. Get a small one if possible.. Everything else looks fine tbf.. Stay safe n gud luck with her.. 👍🍀