condensation

Hi guys just going to jup straight to the issue , ive recently built a grow box ( 1.2mx1.2mx1.8m) its nothing huge but should be plenty if area for my own personal. So it was built using double sheeted 12mm ply walls/roof/floor+ door with 50mm poly insulation between the sheets. Its very sturdy...

Last few weeks, I've noticed a LOT of condensation on the inside of my grow tent. The inside of the tent is basically soaked. What causes this? is this bad? If so, how do I stop? The tent is pretty much all closed up. I opened one of the vents last night, but if it helped, it helped only...