I like the weight of the pot theory. When its dry the pot is very light. It needs water. 1 gallon of water weighs around 8 lbs. That should be easy to tell the difference between wet and dry just by several pounds of weight difference. Under watering is better than overwatering also.
I just pulled a male out of room. I have a feeling it may be too late. What is potential damage done? I have one in 3rd week of flowering and four others very near by, still in veg. I cant believe I didnt catch it sooner but the male sacks were large.