does it look like an overdose or deficiency?

So I checked out your DWC diary, 23 C for water is way too hot, you probably have root rot (Pythium). Above 20 C you're more likely to have root rot. If you're roots are mushy and have a brownish color, it's probably rot. And if you are recirculating water from a reservoir to all your buckets, all your water will be infected with Pythium. Water should ideally be between 17-19 C. Don't submerge your basket in the water, keep 2-4 inches between the water and the basket, roots need to breathe. Make sure you have an air stone that agitates the water enough, as if it were boiling. Avoid light leaks to your roots, light will make the rot proliferate. You can add bacillus (Hydroguard, Monkey Juice, Root Builder), it will help to eat up the rot. Some also use chlorine to keep a sterile environment. You can mix 7g of pool shock to 1 liter of water, then use 1 ml/gal of water of that mix in your reservoir (chlorine ppm should be at 2-5, use pool strips to check ppm). Hope this helps happy growing!

Hi, I've never grown in that medium so I'm only assuming here. Using a medium that requires feeding from the start for a beginner is a tall order. I looked at your other diary and she was struggling quit a bit throughout the grow, especially in flower but you'll learn using this method after several grows. It this was in soil I would say your over watering which could still be the case, also since it not pre fertilized soil it looks like Phosphorous, with the dark stems and veins, Magnesium can give the lighter color between the veins, and your starting to get dead areas along the edges and that could be Potassium. Make sure the basics are in order first. Light power and distance, PH, airflow how your watering. Good Luck