For first 2-4 weeks it is recommended to keep temp as high as 30-35C for maximum co2 benefit. I'm worried about too high root temp in this case. At this stage my plants doesn't cover all that crop area yet and heat penetrates into the roots more easily. It's a coco grow to keep in mind. If roots would be in hydro system, it would be more easy to keep rootzone cooler, but in my coco it measures as high as 26-28C inside the pot (actual rootzone) when there is about 33C everywhere around. One trick would be to water many times a day with cool water (around 18C maybe), but.. Does anyone know what to do in this case? What is a good rootzone temp when gassing with co2 with high temps?