So this is first grow in an actual tent and I'm having a really hard time with temp and humidity.

Running 2 vivosun 4x4 650 lights in a 4x8 tent. It's all setup on a grow hub control, and maybe I'm just watching too much.

With lights on at 80% my temps start at 75°f and then steadily climb to 88°f. The exhaust blower comes on and the temp drops to about 85, and then back up to 88. When the light goes off temps come back down to 73°.

My humidifier is running through almost a gallon of water per day trying to keep the vpd below 1.5 but it's a struggle. The Lung room is perfect at 73°/60%.

I can set the exhaust to run constant when the light is on and keep the temps in check, but am I doing something wrong here? My 4x4 running a small spider farmer light sets at 74° all day long, and the exhaust just kicks on once in a while for air exchange. Is there a specific way to vent these tents I'm missing? I have the bottom screened vents open. It's cool out thos time of year and I can pipe in outside air If I need too.

My plants are growing really slow and look stressed. I'm also growing in coco for the first time, but they did really well in the 4x4 so I think its just wild temps causing me issues.

Any thought on temps? Maybe too much light? It's the recommended light for a 4x8 from vivosun.