looking to buy a 4x8 and the adds for some, if not most, suggest that the new mylar reflective (non-white) are non toxic like the old ones. i have an older white reflective tent and didnt hear about this till now...should i be concerned with the older tent i still use? does the mylar metal looking reflective tents function "30%" better in dispersing the light to the plants? or is this going to increase the heat within the tent? gotta be safe. thanks.