Bigger pots.
I would say chronic under watering with a bit of salt buildup.
They are root bound or close to it and the soil will dry daily quickly.
Either mix your nutes weaker 1/4 - 1/2 strength and feed with every watering until 20% run off or mix the nute 1/2 to full strength and water, feed, water, feed, water, feed, etc until 20% run off.
The ph of soil swings as it dries to allow proper nutrient uptake. Too wet or too dry will cause various problems.
Go by weight. If it feels heavy don't water, if its light water.