Hi everyone... after carefully going through this journal I was struck by the above quote more than anything else that has been said here. I too see constantly droopy plants and as you said, the plants never get excellent lift to show the praying mode that is indicative of full transpiration and healthy roots.
The quoted sentence is why I believe this is happening. All through veg, instead of building stronger roots in those big containers by teasing out the water, you were coddling them by watering way too often, never letting them actually dry out all the way to the bottom. You said it yourself, still moist, except for an inch and a half down. You say the pots are light, but I am saying that they should be way past light... they should be so very light that your human senses, as good as they are, should not be able to tell that there is ANY water weight in there at all. But no, since these are autos, you have started them in huge containers and in there it is very very hard to use the lift method to determine if there is still water in there, and as a result you have consistently watered way too often and probably have had the lower roots covered in stale water throughout most of veg. This is not the proper way to water a weed, no matter if it is a regular or an auto. A coddled weed never will grow robust roots and a weed without a wet/dry cycle will never thrive.
So now you are in bloom and instead of having a robust root ball with a clear wet/dry cycle, you still have the same situation you had in veg... a good portion of your lower roots are still shut down, unable to provide the uptake necessary to lift up all of the leaves. Even though the normal strategy in bloom is to try to start pushing more water at the plants, you need to fix this problem fast because frankly, your plants are not happy. You need to not be afraid to let that soil dry out... watch your plant, but it is my belief that as soon as you finally let the water table fall down into the last inch of that container, drawing oxygen way down deep to those bottom feeder roots, these plants will begin to perk back up. It typically will take 2 or 3 complete wet/dry cycles to get the plant back up to full speed.
Now to make that happen in those huge containers, especially early on with small plants, it might take a week to use up all the water that the soil can hold. With you coming in every 3 or 4 days watering to runoff, it will never dry out. A better strategy would be to come in every 3 or 4 days to water with a smaller amount of water, intending only to water the top set of spreader roots, but not add to the water table down below. I get nervous if I let my top roots dry out for more than 3 or 4 days too, and I call this two stage watering. I will water a couple of times if necessary with about a third of the amount that causes runoff, just to keep the plants metabolism high and those upper roots active, while waiting for the soil to dry out all the way down into the bottom inch of the container. Eventually the bottom will dry out and then a proper full watering of the container to runoff can be done, repeating the process over and over until the top and the bottom sync up and two stage watering can go away.
I hope this helps. Watering incorrectly is the single most common mistake made in the pot world, and getting into messes like this is why I do not endorse the idea of putting autos in the final container right at the start, because without a good understanding of how to properly water this weed, it is so easy for new gardeners to get in exactly the mess you find yourself in today. Soon you will get the knack for this and figure out what it is these plants need from you and you will be able to manage the large containers... but how to do it correctly is not exactly easy to figure out at first.
