Brown/rust spots have been increasing on one of my...

Yes you have calcium deficiencies but don't over do it as you can also have issues with excess. https://www.maximumyield.com/nutrient-deficiencies-and-excesses-in-cannabis-growing/2/17598

Hi @VanBrando! Nice ladies in there 😍 I'm thinking more of a Phosphorous deficiency, considering you're giving loads of nutrients, I think your plants had enough Calcium and Magnesium. My bet is that you're having salts buildup in your medium, because of an intense feeding schedule and probably a lack of runoff, your rootmass is flooded with old nutrients, and is unable to manage nutrients intakes anymore (lockout leading to deficiencies). In this situation I would flush the medium with tap water buffered at pH 6.2, then help the medium to dry by putting a small fan blowing a continuous breeze on the container's surface. Once almost dry, see how this goes, and probably give it a good meal with Phosphorous and Potassium. Affected leaves won't recover but the new ones should be healthy. Hope this will help, keep us updated and happy growing! 👊

Agree that's probably not light stress. Calcium looks like the culprit. Looks like you have your PH in order and are treating it properly. Good luck and happy growing !!🍀💪

You are right seems like calcium deficiency.. hope you get her right..and YOU WILL 😂 Happy growing!

Looks like it could be rust fungus, rust fungus is an air bourn fungus can be caused by poor ventilation and spreads to other hosts, try gettin more ventilation in your grow room. Check everything in your room to make sure it’s working and we’ll ventilated. Trim some lower leaves and get some air movement under your plants. I wouldn’t spray anything unless it’s safe to spray on fruiting crops. Hope this helps good luck with the grow