Sorry that was meant as an attack or anything. Honestly my wife and I have only been growing for 2 years now. This is our 13th grow and our best yet. (If that's saying anything)
We aren't as experienced with growing and often see changes but don't full understand what's going on behind the scenes. Here I try to vocalize what I see in hopes someone with way more experience, such as yourself, can chime in and provide helpful context.
We think the plants are enjoying the lower PPM's much more. The fact they drank over 20 gallons in two days says a lot to us.
As far as the temps go; Lights are on from 6PM to 6AM to help keep temps under control. We go out there right as lights are on, it's still Sunny out and warmer. By the time the sun goes down they drop to 75-77F. The temps are more a reflection of that time then the actual all lights on temp.
We want to run CO2 in all the tents, but, idk we feel kinda ashamed to run it? We know we don't have the skills to maximize the CO2 and don't want to waste it. The Slurricane tent still has CO2 and I think that's why it's doing the best, but again not experienced enough to know.
All good, I didn't take it as anything like that, I just didn't want to be micromanaging your grow, or honestly be held responsible if things took a turn for the worse.
Ppm is one of those things that I generally keep fairly low. Any time I've gone over about 1.5ec or 750ppm on the 0.5 scale I've had more issues than anything. Keeping them between 1.2-1.4 in a vented flower room at around 1000-1100ppfd usually gives me pretty dialed in results. That's also keeping the nutrients very simple.
With regard to your plants drinking more, that's to be expected with the reduction in ec and to me a sign that youve done the right thing.
The ppm of the nutrient solution controls the osmotic pressure on the roots. Osmosis pulls water from a less concentrated solution to a more concentrated solution.
In the case of plant roots, they are full of nutrients and carbohydrates inside the root which generally has a higher concentration of dissolved solids than the nutrient solution itself, so water moves into the plant. As the concentration of nutrients in solution gets higher, the difference in concentration of dissolved solids inside and outside the root becomes less, and so water movement through the root membrane slows down. If nutrient ppm gets too high, it can actually pull water out of the plant.
If nutrient levels are lower, you get a lot more water entering the plant roots. Obviously it's important not to go too low on ppm for the sake of plant health, you still need enough nutrients. But in the last half of flower without using Co2, 1.2-1.3ec is generally more than enough.