You are over watering because you have your hole(s) at 4" from the bottom. I've done 100% hempy buckets in containers of those size and even smaller with good results even with high temps like you. Water once every day or every other. You don't want any water above the hole. After you water, tilt your containers at an angle towards a hole and watch more water poor out to show you how much water it is really holding. Just drill or punch some more holes much lower like around an inch from the bottom.