Root Zone Temp too high for LED Co2 grow in Rockwool, what to do?

So I just switched to LED and from what I understand plants like much higher temps (85-87F, and as high as 96F with co2) because the leaf surface temperature is substantially lower with LED (lack of IR) when compared to HPS.

My room is currently
Phase: Week 1 Flower (Just flipped 12/12)
Medium: Rockwool - Top Feed - Drain to Waste
Nutrients: Full Heavy16 line
Lights: LED Spider Farmer SF-4000
Room Controller: Growtronix System
Light Intensity at Canopy: 600-700PPFD (I want 1000PPFD but lowering lights more will increase root zone temp)
Room Temp: 82F ( I want 90F but again, root zone temp )
Room Humidity: 62% (Following Early Flower VPD chart, see photos)
Co2: 1200 PPM
Leaf Surface Temp: 76F (I want 85F)
Root Zone Temp: 72-77F (I want 69F)

Watering Temp: 62F

All of the "I wants" I can actually make happen except for the root zone temp, it's already higher than I want. From my understanding I should not water lower than 60F. I was crop steering watering, only 1 minute every every 30 minutes but what I found was that water sitting in lines kept heating up from high room temp and lower water temp would never reach the plants because it was such short intervals. I now just water 2 hours after lights on for 11 minutes with two .5gal dripper's and this allows the Rockwool to get some of that cooled down water from res. These temps above are my current configuration but I would like to raise the temps way higher because I am running co2. Only problem is that my root zone is already high and above 75F most of the day and I want the root zone at 69F. Am I too concerned about the root zone temp? Anyone have high root zone temps with no issues? Roots coming out of the Rockwool are slightly brown and I can't tell if its nutrient stain or slight root rot due to higher root zone temps. Any good advice on how to keep a better handle on root zone temp when running high temp with co2? Or does the co2 allow the root zone temp to be higher as well? Thanks in advance for any advice!
 

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Relic79

Well-Known Member
Thanks for asking my advice. I'm not sure I have the experience to guide you but I would say that you might be prematurely optimizing for root temp. Is this the first cycle in the room? Your plants look healthy and happy.

The brown roots are probaby due to light/air exposure. I have seen people cover their cube trays in white poly to keep the light off and reflect heat. I am not sure how you might rig up a shield of sorts under each plant but above the cube....

if it's even needed.....
 
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