To Richard, re: cooling
nutrient.
You can buy a small refrigerator at Sams Club, or perhaps at Walmart for about 100 bucks. Just drill a hole in the side for the nutrient line.
I'm in California and the temp here is usually over a 100 degrees in the hottest months. I'm just finishing up a 16 bottle garden and I don't forsee any problem in keeping the temp of the nutrient the same as ambient air. Seems to me that this would keep the plant from going into shock by being cooled every half hour or so.
If it gets too hot and my present plants in the ground start drooping, I just give them a good watering and they perk up immediately.
No matter what, I'd be interested in how your plants react to a shot of cool nutrient. Keep us posted.
Tailwheel