I'm not seeing any N deficiency but seeing nute burn on a lot.
And you should stop spraying your plants. They don't need it and you make them more likely to get mildew or fungus problems. Also washes out Ca and other nutes from the leaves.
Overall they look healthy for now. What kind of water are you using? Sounds like hard water with the high pH you talked about. Big problems ahead it it is real hard water.
You really need some proper nutes with the right NPK ratios. That 20-20-20 is your best bet for now and later as well. 15-30-15 is way too high in P and I think you are feeding too much and that's why the nute burn tho now that they are bigger they seem to be handling it better. Does Peters make something like a 5-10-20 for better flowering?
A lot of the major nute companies make nutes especially for coco but it doesn't look like they are in coco now in the large pots. I use ProMix and pH Perfect nutes from AN with reverse osmosis water and that works good. Never even test the pH.
Good luck and good growing!