Tenfoil is not ideal, but it will not cook your plantIMO , just hang it up with the dull side reflecting out. I use it in my clone/mother cab with 10k to 15k lums and there is no cooking, but milar is desired for best results, read the FAQ by Zandor on it. Try to use at least 2 gallon buckets for the plants because if the roots do not have enough room then they will not be able to uptake nutes properly and the plants will become stressed as well. When transplanting try to get some powder rooting hormone, you sprinkle it in the hole you are going to move the plant into and sprinkle some on the root ball as well. Get some super thrive to add to the feeding to, it will help to minimize the shok.
Adieu